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* [PATCH] net: usb: Correct PHY handling of smsc95xx
@ 2021-11-22 18:44 Martyn Welch
  2021-11-23 12:40 ` patchwork-bot+netdevbpf
  2021-11-27 17:48 ` Ferry Toth
  0 siblings, 2 replies; 8+ messages in thread
From: Martyn Welch @ 2021-11-22 18:44 UTC (permalink / raw)
  To: netdev
  Cc: linux-usb, linux-kernel, kernel, Martyn Welch, Steve Glendinning,
	UNGLinuxDriver, David S. Miller, Jakub Kicinski, stable

The smsc95xx driver is dropping phy speed settings and causing a stack
trace at device unbind:

[  536.379147] smsc95xx 2-1:1.0 eth1: unregister 'smsc95xx' usb-ci_hdrc.2-1, smsc95xx USB 2.0 Ethernet
[  536.425029] ------------[ cut here ]------------
[  536.429650] WARNING: CPU: 0 PID: 439 at fs/kernfs/dir.c:1535 kernfs_remove_by_name_ns+0xb8/0xc0
[  536.438416] kernfs: can not remove 'attached_dev', no directory
[  536.444363] Modules linked in: xts dm_crypt dm_mod atmel_mxt_ts smsc95xx usbnet
[  536.451748] CPU: 0 PID: 439 Comm: sh Tainted: G        W         5.15.0 #1
[  536.458636] Hardware name: Freescale i.MX53 (Device Tree Support)
[  536.464735] Backtrace: 
[  536.467190] [<80b1c904>] (dump_backtrace) from [<80b1cb48>] (show_stack+0x20/0x24)
[  536.474787]  r7:000005ff r6:8035b294 r5:600f0013 r4:80d8af78
[  536.480449] [<80b1cb28>] (show_stack) from [<80b1f764>] (dump_stack_lvl+0x48/0x54)
[  536.488035] [<80b1f71c>] (dump_stack_lvl) from [<80b1f788>] (dump_stack+0x18/0x1c)
[  536.495620]  r5:00000009 r4:80d9b820
[  536.499198] [<80b1f770>] (dump_stack) from [<80124fac>] (__warn+0xfc/0x114)
[  536.506187] [<80124eb0>] (__warn) from [<80b1d21c>] (warn_slowpath_fmt+0xa8/0xdc)
[  536.513688]  r7:000005ff r6:80d9b820 r5:80d9b8e0 r4:83744000
[  536.519349] [<80b1d178>] (warn_slowpath_fmt) from [<8035b294>] (kernfs_remove_by_name_ns+0xb8/0xc0)
[  536.528416]  r9:00000001 r8:00000000 r7:824926dc r6:00000000 r5:80df6c2c r4:00000000
[  536.536162] [<8035b1dc>] (kernfs_remove_by_name_ns) from [<80b1f56c>] (sysfs_remove_link+0x4c/0x50)
[  536.545225]  r6:7f00f02c r5:80df6c2c r4:83306400
[  536.549845] [<80b1f520>] (sysfs_remove_link) from [<806f9c8c>] (phy_detach+0xfc/0x11c)
[  536.557780]  r5:82492000 r4:83306400
[  536.561359] [<806f9b90>] (phy_detach) from [<806f9cf8>] (phy_disconnect+0x4c/0x58)
[  536.568943]  r7:824926dc r6:7f00f02c r5:82492580 r4:83306400
[  536.574604] [<806f9cac>] (phy_disconnect) from [<7f00a310>] (smsc95xx_disconnect_phy+0x30/0x38 [smsc95xx])
[  536.584290]  r5:82492580 r4:82492580
[  536.587868] [<7f00a2e0>] (smsc95xx_disconnect_phy [smsc95xx]) from [<7f001570>] (usbnet_stop+0x70/0x1a0 [usbnet])
[  536.598161]  r5:82492580 r4:82492000
[  536.601740] [<7f001500>] (usbnet_stop [usbnet]) from [<808baa70>] (__dev_close_many+0xb4/0x12c)
[  536.610466]  r8:83744000 r7:00000000 r6:83744000 r5:83745b74 r4:82492000
[  536.617170] [<808ba9bc>] (__dev_close_many) from [<808bab78>] (dev_close_many+0x90/0x120)
[  536.625365]  r7:00000001 r6:83745b74 r5:83745b8c r4:82492000
[  536.631026] [<808baae8>] (dev_close_many) from [<808bf408>] (unregister_netdevice_many+0x15c/0x704)
[  536.640094]  r9:00000001 r8:81130b98 r7:83745b74 r6:83745bc4 r5:83745b8c r4:82492000
[  536.647840] [<808bf2ac>] (unregister_netdevice_many) from [<808bfa50>] (unregister_netdevice_queue+0xa0/0xe8)
[  536.657775]  r10:8112bcc0 r9:83306c00 r8:83306c80 r7:8291e420 r6:83744000 r5:00000000
[  536.665608]  r4:82492000
[  536.668143] [<808bf9b0>] (unregister_netdevice_queue) from [<808bfac0>] (unregister_netdev+0x28/0x30)
[  536.677381]  r6:7f01003c r5:82492000 r4:82492000
[  536.682000] [<808bfa98>] (unregister_netdev) from [<7f000b40>] (usbnet_disconnect+0x64/0xdc [usbnet])
[  536.691241]  r5:82492000 r4:82492580
[  536.694819] [<7f000adc>] (usbnet_disconnect [usbnet]) from [<8076b958>] (usb_unbind_interface+0x80/0x248)
[  536.704406]  r5:7f01003c r4:83306c80
[  536.707984] [<8076b8d8>] (usb_unbind_interface) from [<8061765c>] (device_release_driver_internal+0x1c4/0x1cc)
[  536.718005]  r10:8112bcc0 r9:80dff1dc r8:83306c80 r7:83744000 r6:7f01003c r5:00000000
[  536.725838]  r4:8291e420
[  536.728373] [<80617498>] (device_release_driver_internal) from [<80617684>] (device_release_driver+0x20/0x24)
[  536.738302]  r7:83744000 r6:810d4f4c r5:8291e420 r4:8176ae30
[  536.743963] [<80617664>] (device_release_driver) from [<806156cc>] (bus_remove_device+0xf0/0x148)
[  536.752858] [<806155dc>] (bus_remove_device) from [<80610018>] (device_del+0x198/0x41c)
[  536.760880]  r7:83744000 r6:8116e2e4 r5:8291e464 r4:8291e420
[  536.766542] [<8060fe80>] (device_del) from [<80768fe8>] (usb_disable_device+0xcc/0x1e0)
[  536.774576]  r10:8112bcc0 r9:80dff1dc r8:00000001 r7:8112bc48 r6:8291e400 r5:00000001
[  536.782410]  r4:83306c00
[  536.784945] [<80768f1c>] (usb_disable_device) from [<80769c30>] (usb_set_configuration+0x514/0x8dc)
[  536.794011]  r10:00000000 r9:00000000 r8:832c3600 r7:00000004 r6:810d5688 r5:00000000
[  536.801844]  r4:83306c00
[  536.804379] [<8076971c>] (usb_set_configuration) from [<80775fac>] (usb_generic_driver_disconnect+0x34/0x38)
[  536.814236]  r10:832c3610 r9:83745ef8 r8:832c3600 r7:00000004 r6:810d5688 r5:83306c00
[  536.822069]  r4:83306c00
[  536.824605] [<80775f78>] (usb_generic_driver_disconnect) from [<8076b850>] (usb_unbind_device+0x30/0x70)
[  536.834100]  r5:83306c00 r4:810d5688
[  536.837678] [<8076b820>] (usb_unbind_device) from [<8061765c>] (device_release_driver_internal+0x1c4/0x1cc)
[  536.847432]  r5:822fb480 r4:83306c80
[  536.851009] [<80617498>] (device_release_driver_internal) from [<806176a8>] (device_driver_detach+0x20/0x24)
[  536.860853]  r7:00000004 r6:810d4f4c r5:810d5688 r4:83306c80
[  536.866515] [<80617688>] (device_driver_detach) from [<80614d98>] (unbind_store+0x70/0xe4)
[  536.874793] [<80614d28>] (unbind_store) from [<80614118>] (drv_attr_store+0x30/0x3c)
[  536.882554]  r7:00000000 r6:00000000 r5:83739200 r4:80614d28
[  536.888217] [<806140e8>] (drv_attr_store) from [<8035cb68>] (sysfs_kf_write+0x48/0x54)
[  536.896154]  r5:83739200 r4:806140e8
[  536.899732] [<8035cb20>] (sysfs_kf_write) from [<8035be84>] (kernfs_fop_write_iter+0x11c/0x1d4)
[  536.908446]  r5:83739200 r4:00000004
[  536.912024] [<8035bd68>] (kernfs_fop_write_iter) from [<802b87fc>] (vfs_write+0x258/0x3e4)
[  536.920317]  r10:00000000 r9:83745f58 r8:83744000 r7:00000000 r6:00000004 r5:00000000
[  536.928151]  r4:82adacc0
[  536.930687] [<802b85a4>] (vfs_write) from [<802b8b0c>] (ksys_write+0x74/0xf4)
[  536.937842]  r10:00000004 r9:007767a0 r8:83744000 r7:00000000 r6:00000000 r5:82adacc0
[  536.945676]  r4:82adacc0
[  536.948213] [<802b8a98>] (ksys_write) from [<802b8ba4>] (sys_write+0x18/0x1c)
[  536.955367]  r10:00000004 r9:83744000 r8:80100244 r7:00000004 r6:76f47b58 r5:76fc0350
[  536.963200]  r4:00000004
[  536.965735] [<802b8b8c>] (sys_write) from [<80100060>] (ret_fast_syscall+0x0/0x48)
[  536.973320] Exception stack(0x83745fa8 to 0x83745ff0)
[  536.978383] 5fa0:                   00000004 76fc0350 00000001 007767a0 00000004 00000000
[  536.986569] 5fc0: 00000004 76fc0350 76f47b58 00000004 76f47c7c 76f48114 00000000 7e87991c
[  536.994753] 5fe0: 00000498 7e879908 76e6dce8 76eca2e8
[  536.999922] ---[ end trace 9b835d809816b435 ]---

The driver should not be connecting and disconnecting the PHY when the
device is opened and closed, it should be stopping and starting the PHY. The
phy should be connected as part of binding and disconnected during
unbinding.

As this results in the PHY not being reset during open, link speed, etc.
settings set prior to the link coming up are now not being lost.

It is necessary for phy_stop() to only be called when the phydev still
exists (resolving the above stack trace). When unbinding, ".unbind" will be
called prior to ".stop", with phy_disconnect() already having called
phy_stop() before the phydev becomes inaccessible.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
Cc: Steve Glendinning <steve.glendinning@shawell.net>
Cc: UNGLinuxDriver@microchip.com
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: stable@kernel.org # v5.15
---
 drivers/net/usb/smsc95xx.c | 55 ++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 29 deletions(-)

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 26b1bd8e845b..f91dabd65ecd 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -1049,6 +1049,14 @@ static const struct net_device_ops smsc95xx_netdev_ops = {
 	.ndo_set_features	= smsc95xx_set_features,
 };
 
+static void smsc95xx_handle_link_change(struct net_device *net)
+{
+	struct usbnet *dev = netdev_priv(net);
+
+	phy_print_status(net->phydev);
+	usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
+}
+
 static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
 {
 	struct smsc95xx_priv *pdata;
@@ -1153,6 +1161,17 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
 	dev->net->min_mtu = ETH_MIN_MTU;
 	dev->net->max_mtu = ETH_DATA_LEN;
 	dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
+
+	ret = phy_connect_direct(dev->net, pdata->phydev,
+				 &smsc95xx_handle_link_change,
+				 PHY_INTERFACE_MODE_MII);
+	if (ret) {
+		netdev_err(dev->net, "can't attach PHY to %s\n", pdata->mdiobus->id);
+		goto unregister_mdio;
+	}
+
+	phy_attached_info(dev->net->phydev);
+
 	return 0;
 
 unregister_mdio:
@@ -1170,47 +1189,25 @@ static void smsc95xx_unbind(struct usbnet *dev, struct usb_interface *intf)
 {
 	struct smsc95xx_priv *pdata = dev->driver_priv;
 
+	phy_disconnect(dev->net->phydev);
 	mdiobus_unregister(pdata->mdiobus);
 	mdiobus_free(pdata->mdiobus);
 	netif_dbg(dev, ifdown, dev->net, "free pdata\n");
 	kfree(pdata);
 }
 
-static void smsc95xx_handle_link_change(struct net_device *net)
-{
-	struct usbnet *dev = netdev_priv(net);
-
-	phy_print_status(net->phydev);
-	usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
-}
-
 static int smsc95xx_start_phy(struct usbnet *dev)
 {
-	struct smsc95xx_priv *pdata = dev->driver_priv;
-	struct net_device *net = dev->net;
-	int ret;
+	phy_start(dev->net->phydev);
 
-	ret = smsc95xx_reset(dev);
-	if (ret < 0)
-		return ret;
-
-	ret = phy_connect_direct(net, pdata->phydev,
-				 &smsc95xx_handle_link_change,
-				 PHY_INTERFACE_MODE_MII);
-	if (ret) {
-		netdev_err(net, "can't attach PHY to %s\n", pdata->mdiobus->id);
-		return ret;
-	}
-
-	phy_attached_info(net->phydev);
-	phy_start(net->phydev);
 	return 0;
 }
 
-static int smsc95xx_disconnect_phy(struct usbnet *dev)
+static int smsc95xx_stop(struct usbnet *dev)
 {
-	phy_stop(dev->net->phydev);
-	phy_disconnect(dev->net->phydev);
+	if (dev->net->phydev)
+		phy_stop(dev->net->phydev);
+
 	return 0;
 }
 
@@ -1965,7 +1962,7 @@ static const struct driver_info smsc95xx_info = {
 	.unbind		= smsc95xx_unbind,
 	.link_reset	= smsc95xx_link_reset,
 	.reset		= smsc95xx_start_phy,
-	.stop		= smsc95xx_disconnect_phy,
+	.stop		= smsc95xx_stop,
 	.rx_fixup	= smsc95xx_rx_fixup,
 	.tx_fixup	= smsc95xx_tx_fixup,
 	.status		= smsc95xx_status,
-- 
2.27.0


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] net: usb: Correct PHY handling of smsc95xx
  2021-11-22 18:44 [PATCH] net: usb: Correct PHY handling of smsc95xx Martyn Welch
@ 2021-11-23 12:40 ` patchwork-bot+netdevbpf
  2021-11-27 17:48 ` Ferry Toth
  1 sibling, 0 replies; 8+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-11-23 12:40 UTC (permalink / raw)
  To: Martyn Welch
  Cc: netdev, linux-usb, linux-kernel, kernel, steve.glendinning,
	UNGLinuxDriver, davem, kuba, stable

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Mon, 22 Nov 2021 18:44:45 +0000 you wrote:
> The smsc95xx driver is dropping phy speed settings and causing a stack
> trace at device unbind:
> 
> [  536.379147] smsc95xx 2-1:1.0 eth1: unregister 'smsc95xx' usb-ci_hdrc.2-1, smsc95xx USB 2.0 Ethernet
> [  536.425029] ------------[ cut here ]------------
> [  536.429650] WARNING: CPU: 0 PID: 439 at fs/kernfs/dir.c:1535 kernfs_remove_by_name_ns+0xb8/0xc0
> [  536.438416] kernfs: can not remove 'attached_dev', no directory
> [  536.444363] Modules linked in: xts dm_crypt dm_mod atmel_mxt_ts smsc95xx usbnet
> [  536.451748] CPU: 0 PID: 439 Comm: sh Tainted: G        W         5.15.0 #1
> [  536.458636] Hardware name: Freescale i.MX53 (Device Tree Support)
> [  536.464735] Backtrace:
> [  536.467190] [<80b1c904>] (dump_backtrace) from [<80b1cb48>] (show_stack+0x20/0x24)
> [  536.474787]  r7:000005ff r6:8035b294 r5:600f0013 r4:80d8af78
> [  536.480449] [<80b1cb28>] (show_stack) from [<80b1f764>] (dump_stack_lvl+0x48/0x54)
> [  536.488035] [<80b1f71c>] (dump_stack_lvl) from [<80b1f788>] (dump_stack+0x18/0x1c)
> [  536.495620]  r5:00000009 r4:80d9b820
> [  536.499198] [<80b1f770>] (dump_stack) from [<80124fac>] (__warn+0xfc/0x114)
> [  536.506187] [<80124eb0>] (__warn) from [<80b1d21c>] (warn_slowpath_fmt+0xa8/0xdc)
> [  536.513688]  r7:000005ff r6:80d9b820 r5:80d9b8e0 r4:83744000
> [  536.519349] [<80b1d178>] (warn_slowpath_fmt) from [<8035b294>] (kernfs_remove_by_name_ns+0xb8/0xc0)
> [  536.528416]  r9:00000001 r8:00000000 r7:824926dc r6:00000000 r5:80df6c2c r4:00000000
> [  536.536162] [<8035b1dc>] (kernfs_remove_by_name_ns) from [<80b1f56c>] (sysfs_remove_link+0x4c/0x50)
> [  536.545225]  r6:7f00f02c r5:80df6c2c r4:83306400
> [  536.549845] [<80b1f520>] (sysfs_remove_link) from [<806f9c8c>] (phy_detach+0xfc/0x11c)
> [  536.557780]  r5:82492000 r4:83306400
> [  536.561359] [<806f9b90>] (phy_detach) from [<806f9cf8>] (phy_disconnect+0x4c/0x58)
> [  536.568943]  r7:824926dc r6:7f00f02c r5:82492580 r4:83306400
> [  536.574604] [<806f9cac>] (phy_disconnect) from [<7f00a310>] (smsc95xx_disconnect_phy+0x30/0x38 [smsc95xx])
> [  536.584290]  r5:82492580 r4:82492580
> [  536.587868] [<7f00a2e0>] (smsc95xx_disconnect_phy [smsc95xx]) from [<7f001570>] (usbnet_stop+0x70/0x1a0 [usbnet])
> [  536.598161]  r5:82492580 r4:82492000
> [  536.601740] [<7f001500>] (usbnet_stop [usbnet]) from [<808baa70>] (__dev_close_many+0xb4/0x12c)
> [  536.610466]  r8:83744000 r7:00000000 r6:83744000 r5:83745b74 r4:82492000
> [  536.617170] [<808ba9bc>] (__dev_close_many) from [<808bab78>] (dev_close_many+0x90/0x120)
> [  536.625365]  r7:00000001 r6:83745b74 r5:83745b8c r4:82492000
> [  536.631026] [<808baae8>] (dev_close_many) from [<808bf408>] (unregister_netdevice_many+0x15c/0x704)
> [  536.640094]  r9:00000001 r8:81130b98 r7:83745b74 r6:83745bc4 r5:83745b8c r4:82492000
> [  536.647840] [<808bf2ac>] (unregister_netdevice_many) from [<808bfa50>] (unregister_netdevice_queue+0xa0/0xe8)
> [  536.657775]  r10:8112bcc0 r9:83306c00 r8:83306c80 r7:8291e420 r6:83744000 r5:00000000
> [  536.665608]  r4:82492000
> [  536.668143] [<808bf9b0>] (unregister_netdevice_queue) from [<808bfac0>] (unregister_netdev+0x28/0x30)
> [  536.677381]  r6:7f01003c r5:82492000 r4:82492000
> [  536.682000] [<808bfa98>] (unregister_netdev) from [<7f000b40>] (usbnet_disconnect+0x64/0xdc [usbnet])
> [  536.691241]  r5:82492000 r4:82492580
> [  536.694819] [<7f000adc>] (usbnet_disconnect [usbnet]) from [<8076b958>] (usb_unbind_interface+0x80/0x248)
> [  536.704406]  r5:7f01003c r4:83306c80
> [  536.707984] [<8076b8d8>] (usb_unbind_interface) from [<8061765c>] (device_release_driver_internal+0x1c4/0x1cc)
> [  536.718005]  r10:8112bcc0 r9:80dff1dc r8:83306c80 r7:83744000 r6:7f01003c r5:00000000
> [  536.725838]  r4:8291e420
> [  536.728373] [<80617498>] (device_release_driver_internal) from [<80617684>] (device_release_driver+0x20/0x24)
> [  536.738302]  r7:83744000 r6:810d4f4c r5:8291e420 r4:8176ae30
> [  536.743963] [<80617664>] (device_release_driver) from [<806156cc>] (bus_remove_device+0xf0/0x148)
> [  536.752858] [<806155dc>] (bus_remove_device) from [<80610018>] (device_del+0x198/0x41c)
> [  536.760880]  r7:83744000 r6:8116e2e4 r5:8291e464 r4:8291e420
> [  536.766542] [<8060fe80>] (device_del) from [<80768fe8>] (usb_disable_device+0xcc/0x1e0)
> [  536.774576]  r10:8112bcc0 r9:80dff1dc r8:00000001 r7:8112bc48 r6:8291e400 r5:00000001
> [  536.782410]  r4:83306c00
> [  536.784945] [<80768f1c>] (usb_disable_device) from [<80769c30>] (usb_set_configuration+0x514/0x8dc)
> [  536.794011]  r10:00000000 r9:00000000 r8:832c3600 r7:00000004 r6:810d5688 r5:00000000
> [  536.801844]  r4:83306c00
> [  536.804379] [<8076971c>] (usb_set_configuration) from [<80775fac>] (usb_generic_driver_disconnect+0x34/0x38)
> [  536.814236]  r10:832c3610 r9:83745ef8 r8:832c3600 r7:00000004 r6:810d5688 r5:83306c00
> [  536.822069]  r4:83306c00
> [  536.824605] [<80775f78>] (usb_generic_driver_disconnect) from [<8076b850>] (usb_unbind_device+0x30/0x70)
> [  536.834100]  r5:83306c00 r4:810d5688
> [  536.837678] [<8076b820>] (usb_unbind_device) from [<8061765c>] (device_release_driver_internal+0x1c4/0x1cc)
> [  536.847432]  r5:822fb480 r4:83306c80
> [  536.851009] [<80617498>] (device_release_driver_internal) from [<806176a8>] (device_driver_detach+0x20/0x24)
> [  536.860853]  r7:00000004 r6:810d4f4c r5:810d5688 r4:83306c80
> [  536.866515] [<80617688>] (device_driver_detach) from [<80614d98>] (unbind_store+0x70/0xe4)
> [  536.874793] [<80614d28>] (unbind_store) from [<80614118>] (drv_attr_store+0x30/0x3c)
> [  536.882554]  r7:00000000 r6:00000000 r5:83739200 r4:80614d28
> [  536.888217] [<806140e8>] (drv_attr_store) from [<8035cb68>] (sysfs_kf_write+0x48/0x54)
> [  536.896154]  r5:83739200 r4:806140e8
> [  536.899732] [<8035cb20>] (sysfs_kf_write) from [<8035be84>] (kernfs_fop_write_iter+0x11c/0x1d4)
> [  536.908446]  r5:83739200 r4:00000004
> [  536.912024] [<8035bd68>] (kernfs_fop_write_iter) from [<802b87fc>] (vfs_write+0x258/0x3e4)
> [  536.920317]  r10:00000000 r9:83745f58 r8:83744000 r7:00000000 r6:00000004 r5:00000000
> [  536.928151]  r4:82adacc0
> [  536.930687] [<802b85a4>] (vfs_write) from [<802b8b0c>] (ksys_write+0x74/0xf4)
> [  536.937842]  r10:00000004 r9:007767a0 r8:83744000 r7:00000000 r6:00000000 r5:82adacc0
> [  536.945676]  r4:82adacc0
> [  536.948213] [<802b8a98>] (ksys_write) from [<802b8ba4>] (sys_write+0x18/0x1c)
> [  536.955367]  r10:00000004 r9:83744000 r8:80100244 r7:00000004 r6:76f47b58 r5:76fc0350
> [  536.963200]  r4:00000004
> [  536.965735] [<802b8b8c>] (sys_write) from [<80100060>] (ret_fast_syscall+0x0/0x48)
> [  536.973320] Exception stack(0x83745fa8 to 0x83745ff0)
> [  536.978383] 5fa0:                   00000004 76fc0350 00000001 007767a0 00000004 00000000
> [  536.986569] 5fc0: 00000004 76fc0350 76f47b58 00000004 76f47c7c 76f48114 00000000 7e87991c
> [  536.994753] 5fe0: 00000498 7e879908 76e6dce8 76eca2e8
> [  536.999922] ---[ end trace 9b835d809816b435 ]---
> 
> [...]

Here is the summary with links:
  - net: usb: Correct PHY handling of smsc95xx
    https://git.kernel.org/netdev/net/c/a049a30fc27c

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] net: usb: Correct PHY handling of smsc95xx
  2021-11-22 18:44 [PATCH] net: usb: Correct PHY handling of smsc95xx Martyn Welch
  2021-11-23 12:40 ` patchwork-bot+netdevbpf
@ 2021-11-27 17:48 ` Ferry Toth
  2021-11-29 12:08   ` Martyn Welch
  1 sibling, 1 reply; 8+ messages in thread
From: Ferry Toth @ 2021-11-27 17:48 UTC (permalink / raw)
  To: Martyn Welch, netdev
  Cc: linux-usb, linux-kernel, kernel, Steve Glendinning,
	UNGLinuxDriver, David S. Miller, Jakub Kicinski, stable

Hi,

Op 22-11-2021 om 19:44 schreef Martyn Welch:
> The smsc95xx driver is dropping phy speed settings and causing a stack
> trace at device unbind:
> 
> [  536.379147] smsc95xx 2-1:1.0 eth1: unregister 'smsc95xx' usb-ci_hdrc.2-1, smsc95xx USB 2.0 Ethernet
> [  536.425029] ------------[ cut here ]------------
> [  536.429650] WARNING: CPU: 0 PID: 439 at fs/kernfs/dir.c:1535 kernfs_remove_by_name_ns+0xb8/0xc0
> [  536.438416] kernfs: can not remove 'attached_dev', no directory
> [  536.444363] Modules linked in: xts dm_crypt dm_mod atmel_mxt_ts smsc95xx usbnet
> [  536.451748] CPU: 0 PID: 439 Comm: sh Tainted: G        W         5.15.0 #1
> [  536.458636] Hardware name: Freescale i.MX53 (Device Tree Support)
> [  536.464735] Backtrace:
> [  536.467190] [<80b1c904>] (dump_backtrace) from [<80b1cb48>] (show_stack+0x20/0x24)
> [  536.474787]  r7:000005ff r6:8035b294 r5:600f0013 r4:80d8af78
> [  536.480449] [<80b1cb28>] (show_stack) from [<80b1f764>] (dump_stack_lvl+0x48/0x54)
> [  536.488035] [<80b1f71c>] (dump_stack_lvl) from [<80b1f788>] (dump_stack+0x18/0x1c)
> [  536.495620]  r5:00000009 r4:80d9b820
> [  536.499198] [<80b1f770>] (dump_stack) from [<80124fac>] (__warn+0xfc/0x114)
> [  536.506187] [<80124eb0>] (__warn) from [<80b1d21c>] (warn_slowpath_fmt+0xa8/0xdc)
> [  536.513688]  r7:000005ff r6:80d9b820 r5:80d9b8e0 r4:83744000
> [  536.519349] [<80b1d178>] (warn_slowpath_fmt) from [<8035b294>] (kernfs_remove_by_name_ns+0xb8/0xc0)
> [  536.528416]  r9:00000001 r8:00000000 r7:824926dc r6:00000000 r5:80df6c2c r4:00000000
> [  536.536162] [<8035b1dc>] (kernfs_remove_by_name_ns) from [<80b1f56c>] (sysfs_remove_link+0x4c/0x50)
> [  536.545225]  r6:7f00f02c r5:80df6c2c r4:83306400
> [  536.549845] [<80b1f520>] (sysfs_remove_link) from [<806f9c8c>] (phy_detach+0xfc/0x11c)
> [  536.557780]  r5:82492000 r4:83306400
> [  536.561359] [<806f9b90>] (phy_detach) from [<806f9cf8>] (phy_disconnect+0x4c/0x58)
> [  536.568943]  r7:824926dc r6:7f00f02c r5:82492580 r4:83306400
> [  536.574604] [<806f9cac>] (phy_disconnect) from [<7f00a310>] (smsc95xx_disconnect_phy+0x30/0x38 [smsc95xx])
> [  536.584290]  r5:82492580 r4:82492580
> [  536.587868] [<7f00a2e0>] (smsc95xx_disconnect_phy [smsc95xx]) from [<7f001570>] (usbnet_stop+0x70/0x1a0 [usbnet])
> [  536.598161]  r5:82492580 r4:82492000
> [  536.601740] [<7f001500>] (usbnet_stop [usbnet]) from [<808baa70>] (__dev_close_many+0xb4/0x12c)
> [  536.610466]  r8:83744000 r7:00000000 r6:83744000 r5:83745b74 r4:82492000
> [  536.617170] [<808ba9bc>] (__dev_close_many) from [<808bab78>] (dev_close_many+0x90/0x120)
> [  536.625365]  r7:00000001 r6:83745b74 r5:83745b8c r4:82492000
> [  536.631026] [<808baae8>] (dev_close_many) from [<808bf408>] (unregister_netdevice_many+0x15c/0x704)
> [  536.640094]  r9:00000001 r8:81130b98 r7:83745b74 r6:83745bc4 r5:83745b8c r4:82492000
> [  536.647840] [<808bf2ac>] (unregister_netdevice_many) from [<808bfa50>] (unregister_netdevice_queue+0xa0/0xe8)
> [  536.657775]  r10:8112bcc0 r9:83306c00 r8:83306c80 r7:8291e420 r6:83744000 r5:00000000
> [  536.665608]  r4:82492000
> [  536.668143] [<808bf9b0>] (unregister_netdevice_queue) from [<808bfac0>] (unregister_netdev+0x28/0x30)
> [  536.677381]  r6:7f01003c r5:82492000 r4:82492000
> [  536.682000] [<808bfa98>] (unregister_netdev) from [<7f000b40>] (usbnet_disconnect+0x64/0xdc [usbnet])
> [  536.691241]  r5:82492000 r4:82492580
> [  536.694819] [<7f000adc>] (usbnet_disconnect [usbnet]) from [<8076b958>] (usb_unbind_interface+0x80/0x248)
> [  536.704406]  r5:7f01003c r4:83306c80
> [  536.707984] [<8076b8d8>] (usb_unbind_interface) from [<8061765c>] (device_release_driver_internal+0x1c4/0x1cc)
> [  536.718005]  r10:8112bcc0 r9:80dff1dc r8:83306c80 r7:83744000 r6:7f01003c r5:00000000
> [  536.725838]  r4:8291e420
> [  536.728373] [<80617498>] (device_release_driver_internal) from [<80617684>] (device_release_driver+0x20/0x24)
> [  536.738302]  r7:83744000 r6:810d4f4c r5:8291e420 r4:8176ae30
> [  536.743963] [<80617664>] (device_release_driver) from [<806156cc>] (bus_remove_device+0xf0/0x148)
> [  536.752858] [<806155dc>] (bus_remove_device) from [<80610018>] (device_del+0x198/0x41c)
> [  536.760880]  r7:83744000 r6:8116e2e4 r5:8291e464 r4:8291e420
> [  536.766542] [<8060fe80>] (device_del) from [<80768fe8>] (usb_disable_device+0xcc/0x1e0)
> [  536.774576]  r10:8112bcc0 r9:80dff1dc r8:00000001 r7:8112bc48 r6:8291e400 r5:00000001
> [  536.782410]  r4:83306c00
> [  536.784945] [<80768f1c>] (usb_disable_device) from [<80769c30>] (usb_set_configuration+0x514/0x8dc)
> [  536.794011]  r10:00000000 r9:00000000 r8:832c3600 r7:00000004 r6:810d5688 r5:00000000
> [  536.801844]  r4:83306c00
> [  536.804379] [<8076971c>] (usb_set_configuration) from [<80775fac>] (usb_generic_driver_disconnect+0x34/0x38)
> [  536.814236]  r10:832c3610 r9:83745ef8 r8:832c3600 r7:00000004 r6:810d5688 r5:83306c00
> [  536.822069]  r4:83306c00
> [  536.824605] [<80775f78>] (usb_generic_driver_disconnect) from [<8076b850>] (usb_unbind_device+0x30/0x70)
> [  536.834100]  r5:83306c00 r4:810d5688
> [  536.837678] [<8076b820>] (usb_unbind_device) from [<8061765c>] (device_release_driver_internal+0x1c4/0x1cc)
> [  536.847432]  r5:822fb480 r4:83306c80
> [  536.851009] [<80617498>] (device_release_driver_internal) from [<806176a8>] (device_driver_detach+0x20/0x24)
> [  536.860853]  r7:00000004 r6:810d4f4c r5:810d5688 r4:83306c80
> [  536.866515] [<80617688>] (device_driver_detach) from [<80614d98>] (unbind_store+0x70/0xe4)
> [  536.874793] [<80614d28>] (unbind_store) from [<80614118>] (drv_attr_store+0x30/0x3c)
> [  536.882554]  r7:00000000 r6:00000000 r5:83739200 r4:80614d28
> [  536.888217] [<806140e8>] (drv_attr_store) from [<8035cb68>] (sysfs_kf_write+0x48/0x54)
> [  536.896154]  r5:83739200 r4:806140e8
> [  536.899732] [<8035cb20>] (sysfs_kf_write) from [<8035be84>] (kernfs_fop_write_iter+0x11c/0x1d4)
> [  536.908446]  r5:83739200 r4:00000004
> [  536.912024] [<8035bd68>] (kernfs_fop_write_iter) from [<802b87fc>] (vfs_write+0x258/0x3e4)
> [  536.920317]  r10:00000000 r9:83745f58 r8:83744000 r7:00000000 r6:00000004 r5:00000000
> [  536.928151]  r4:82adacc0
> [  536.930687] [<802b85a4>] (vfs_write) from [<802b8b0c>] (ksys_write+0x74/0xf4)
> [  536.937842]  r10:00000004 r9:007767a0 r8:83744000 r7:00000000 r6:00000000 r5:82adacc0
> [  536.945676]  r4:82adacc0
> [  536.948213] [<802b8a98>] (ksys_write) from [<802b8ba4>] (sys_write+0x18/0x1c)
> [  536.955367]  r10:00000004 r9:83744000 r8:80100244 r7:00000004 r6:76f47b58 r5:76fc0350
> [  536.963200]  r4:00000004
> [  536.965735] [<802b8b8c>] (sys_write) from [<80100060>] (ret_fast_syscall+0x0/0x48)
> [  536.973320] Exception stack(0x83745fa8 to 0x83745ff0)
> [  536.978383] 5fa0:                   00000004 76fc0350 00000001 007767a0 00000004 00000000
> [  536.986569] 5fc0: 00000004 76fc0350 76f47b58 00000004 76f47c7c 76f48114 00000000 7e87991c
> [  536.994753] 5fe0: 00000498 7e879908 76e6dce8 76eca2e8
> [  536.999922] ---[ end trace 9b835d809816b435 ]---

I am testing this patch on Intel Edison-Arduino with Linux 5.15.1.
I had reported this issue earlier as
https://lore.kernel.org/linux-usb/07628a9b-1370-98b7-c1f3-98b9bf8cc38f@gmail.com/

This patch indeed resolves the above crash on each unplug.

> The driver should not be connecting and disconnecting the PHY when the
> device is opened and closed, it should be stopping and starting the PHY. The
> phy should be connected as part of binding and disconnected during
> unbinding.
> 
> As this results in the PHY not being reset during open, link speed, etc.
> settings set prior to the link coming up are now not being lost.
> 
> It is necessary for phy_stop() to only be called when the phydev still
> exists (resolving the above stack trace). When unbinding, ".unbind" will be
> called prior to ".stop", with phy_disconnect() already having called
> phy_stop() before the phydev becomes inaccessible.

The patch introduces a new error on each unplug:

usb 1-1: USB disconnect, device number 2
usb 1-1.1: USB disconnect, device number 3
smsc95xx 1-1.1:1.0 eth0: unregister 'smsc95xx' usb-xhci-hcd.1.auto-1.1, 
smsc95xx USB 2.0 Ethernet
smsc95xx 1-1.1:1.0 eth0: Link is Down
smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup

Also as reported earlier, (only) on first plug the more worrying but 
possibly unrelated crash still happens:
------------[ cut here ]------------
DMA-API: xhci-hcd xhci-hcd.1.auto: cacheline tracking EEXIST, 
overlapping mappings aren't supported
WARNING: CPU: 0 PID: 23 at kernel/dma/debug.c:570 add_dma_entry+0x1d9/0x270
Modules linked in: rfcomm iptable_nat bnep usb_f_uac2 u_audio 
snd_sof_nocodec usb_f_mass_storage usb_f_eem u_ether spi_pxa2xx_platform 
dw_dmac usb_f_serial u_serial libcomposite intel_mrfld_pwrbtn 
snd_sof_pci_intel_tng pwm_lpss_pci intel_mrfld_adc pwm_lpss snd_sof_pci 
snd_sof_intel_ipc snd_sof_intel_atom dw_dmac_pci dw_dmac_core snd_sof 
snd_sof_xtensa_dsp snd_soc_acpi spi_pxa2xx_pci brcmfmac brcmutil 
hci_uart leds_gpio btbcm ti_ads7950 industrialio_triggered_buffer 
kfifo_buf tun ledtrig_timer ledtrig_heartbeat mmc_block 
extcon_intel_mrfld sdhci_pci cqhci sdhci led_class mmc_core 
intel_soc_pmic_mrfld btrfs libcrc32c xor zstd_compress zlib_deflate raid6_pq
CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 5.15.1-edison-acpi-standard #1
Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 
2015.01.21:18.19.48
Workqueue: usb_hub_wq hub_event
RIP: 0010:add_dma_entry+0x1d9/0x270
Code: ff 0f 84 97 00 00 00 4c 8b 67 50 4d 85 e4 75 03 4c 8b 27 e8 39 ff 
52 00 48 89 c6 4c 89 e2 48 c7 c7 f0 ab e7 a7 e8 c7 5c b5 00 <0f> 0b 48 
85 ed 0f 85 a4 b3 b5 00 8b 05 46 38 9f 01 85 c0 0f 85 df
RSP: 0000:ffffb047400cfac8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffff9e25fe217478
RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9e25fe217470
RBP: ffff9e25c12ff780 R08: ffffffffa83359a8 R09: 0000000000009ffb
R10: 00000000ffffe000 R11: 3fffffffffffffff R12: ffff9e25c8a24040
R13: 0000000000000001 R14: 0000000000000206 R15: 00000000000f8be4
FS:  0000000000000000(0000) GS:ffff9e25fe200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f62c6d586d8 CR3: 0000000002f3c000 CR4: 00000000001006f0
Call Trace:
  dma_map_page_attrs+0xfb/0x250
  ? usb_hcd_link_urb_to_ep+0x14/0xa0
  usb_hcd_map_urb_for_dma+0x3b1/0x4e0
  usb_hcd_submit_urb+0x93/0xbb0
  ? create_prof_cpu_mask+0x20/0x20
  ? arch_stack_walk+0x73/0xf0
  ? usb_hcd_link_urb_to_ep+0x14/0xa0
  ? prepare_transfer+0xff/0x140
  usb_start_wait_urb+0x60/0x160
  usb_control_msg+0xda/0x140
  hub_ext_port_status+0x82/0x100
  hub_event+0x1b1/0x1830
  ? hub_activate+0x58c/0x860
  process_one_work+0x1d4/0x370
  worker_thread+0x48/0x3d0
  ? rescuer_thread+0x360/0x360
  kthread+0x122/0x140
  ? set_kthread_struct+0x40/0x40
  ret_from_fork+0x22/0x30
---[ end trace da6ffcd9fad23a74 ]---
DMA-API: Mapped at:
  debug_dma_map_page+0x60/0xf0
  dma_map_page_attrs+0xfb/0x250
  usb_hcd_map_urb_for_dma+0x3b1/0x4e0
  usb_hcd_submit_urb+0x93/0xbb0
  usb_start_wait_urb+0x60/0x160
usb 1-1.1: new high-speed USB device number 3 using xhci-hcd
usb 1-1.1: New USB device found, idVendor=0424, idProduct=ec00, 
bcdDevice= 2.00
usb 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1.1: Product: LAN9514
usb 1-1.1: Manufacturer: SMSC
usb 1-1.1: SerialNumber: 00951d0d



> Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
> Cc: Steve Glendinning <steve.glendinning@shawell.net>
> Cc: UNGLinuxDriver@microchip.com
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: stable@kernel.org # v5.15
> ---
>   drivers/net/usb/smsc95xx.c | 55 ++++++++++++++++++--------------------
>   1 file changed, 26 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
> index 26b1bd8e845b..f91dabd65ecd 100644
> --- a/drivers/net/usb/smsc95xx.c
> +++ b/drivers/net/usb/smsc95xx.c
> @@ -1049,6 +1049,14 @@ static const struct net_device_ops smsc95xx_netdev_ops = {
>   	.ndo_set_features	= smsc95xx_set_features,
>   };
>   
> +static void smsc95xx_handle_link_change(struct net_device *net)
> +{
> +	struct usbnet *dev = netdev_priv(net);
> +
> +	phy_print_status(net->phydev);
> +	usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
> +}
> +
>   static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
>   {
>   	struct smsc95xx_priv *pdata;
> @@ -1153,6 +1161,17 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
>   	dev->net->min_mtu = ETH_MIN_MTU;
>   	dev->net->max_mtu = ETH_DATA_LEN;
>   	dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
> +
> +	ret = phy_connect_direct(dev->net, pdata->phydev,
> +				 &smsc95xx_handle_link_change,
> +				 PHY_INTERFACE_MODE_MII);
> +	if (ret) {
> +		netdev_err(dev->net, "can't attach PHY to %s\n", pdata->mdiobus->id);
> +		goto unregister_mdio;
> +	}
> +
> +	phy_attached_info(dev->net->phydev);
> +
>   	return 0;
>   
>   unregister_mdio:
> @@ -1170,47 +1189,25 @@ static void smsc95xx_unbind(struct usbnet *dev, struct usb_interface *intf)
>   {
>   	struct smsc95xx_priv *pdata = dev->driver_priv;
>   
> +	phy_disconnect(dev->net->phydev);
>   	mdiobus_unregister(pdata->mdiobus);
>   	mdiobus_free(pdata->mdiobus);
>   	netif_dbg(dev, ifdown, dev->net, "free pdata\n");
>   	kfree(pdata);
>   }
>   
> -static void smsc95xx_handle_link_change(struct net_device *net)
> -{
> -	struct usbnet *dev = netdev_priv(net);
> -
> -	phy_print_status(net->phydev);
> -	usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
> -}
> -
>   static int smsc95xx_start_phy(struct usbnet *dev)
>   {
> -	struct smsc95xx_priv *pdata = dev->driver_priv;
> -	struct net_device *net = dev->net;
> -	int ret;
> +	phy_start(dev->net->phydev);
>   
> -	ret = smsc95xx_reset(dev);
> -	if (ret < 0)
> -		return ret;
> -
> -	ret = phy_connect_direct(net, pdata->phydev,
> -				 &smsc95xx_handle_link_change,
> -				 PHY_INTERFACE_MODE_MII);
> -	if (ret) {
> -		netdev_err(net, "can't attach PHY to %s\n", pdata->mdiobus->id);
> -		return ret;
> -	}
> -
> -	phy_attached_info(net->phydev);
> -	phy_start(net->phydev);
>   	return 0;
>   }
>   
> -static int smsc95xx_disconnect_phy(struct usbnet *dev)
> +static int smsc95xx_stop(struct usbnet *dev)
>   {
> -	phy_stop(dev->net->phydev);
> -	phy_disconnect(dev->net->phydev);
> +	if (dev->net->phydev)
> +		phy_stop(dev->net->phydev);
> +
>   	return 0;
>   }
>   
> @@ -1965,7 +1962,7 @@ static const struct driver_info smsc95xx_info = {
>   	.unbind		= smsc95xx_unbind,
>   	.link_reset	= smsc95xx_link_reset,
>   	.reset		= smsc95xx_start_phy,
> -	.stop		= smsc95xx_disconnect_phy,
> +	.stop		= smsc95xx_stop,
>   	.rx_fixup	= smsc95xx_rx_fixup,
>   	.tx_fixup	= smsc95xx_tx_fixup,
>   	.status		= smsc95xx_status,
> 


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] net: usb: Correct PHY handling of smsc95xx
  2021-11-27 17:48 ` Ferry Toth
@ 2021-11-29 12:08   ` Martyn Welch
       [not found]     ` <6a06e3b7-df08-6ec0-6e74-95c21fa43f38@gmail.com>
  0 siblings, 1 reply; 8+ messages in thread
From: Martyn Welch @ 2021-11-29 12:08 UTC (permalink / raw)
  To: Ferry Toth, netdev
  Cc: linux-usb, linux-kernel, kernel, Steve Glendinning,
	UNGLinuxDriver, David S. Miller, Jakub Kicinski, stable

On Sat, 2021-11-27 at 18:48 +0100, Ferry Toth wrote:
> Hi,
> 
> Op 22-11-2021 om 19:44 schreef Martyn Welch:
> > The smsc95xx driver is dropping phy speed settings and causing a
> > stack
> > trace at device unbind:
> > 
> > [  536.379147] smsc95xx 2-1:1.0 eth1: unregister 'smsc95xx' usb-
> > ci_hdrc.2-1, smsc95xx USB 2.0 Ethernet
> > [  536.425029] ------------[ cut here ]------------
> > [  536.429650] WARNING: CPU: 0 PID: 439 at fs/kernfs/dir.c:1535
> > kernfs_remove_by_name_ns+0xb8/0xc0
> > [  536.438416] kernfs: can not remove 'attached_dev', no directory
> > [  536.444363] Modules linked in: xts dm_crypt dm_mod atmel_mxt_ts
> > smsc95xx usbnet
> > [  536.451748] CPU: 0 PID: 439 Comm: sh Tainted: G        W        
> > 5.15.0 #1
> > [  536.458636] Hardware name: Freescale i.MX53 (Device Tree
> > Support)
> > [  536.464735] Backtrace:
> > [  536.467190] [<80b1c904>] (dump_backtrace) from [<80b1cb48>]
> > (show_stack+0x20/0x24)
> > [  536.474787]  r7:000005ff r6:8035b294 r5:600f0013 r4:80d8af78
> > [  536.480449] [<80b1cb28>] (show_stack) from [<80b1f764>]
> > (dump_stack_lvl+0x48/0x54)
> > [  536.488035] [<80b1f71c>] (dump_stack_lvl) from [<80b1f788>]
> > (dump_stack+0x18/0x1c)
> > [  536.495620]  r5:00000009 r4:80d9b820
> > [  536.499198] [<80b1f770>] (dump_stack) from [<80124fac>]
> > (__warn+0xfc/0x114)
> > [  536.506187] [<80124eb0>] (__warn) from [<80b1d21c>]
> > (warn_slowpath_fmt+0xa8/0xdc)
> > [  536.513688]  r7:000005ff r6:80d9b820 r5:80d9b8e0 r4:83744000
> > [  536.519349] [<80b1d178>] (warn_slowpath_fmt) from [<8035b294>]
> > (kernfs_remove_by_name_ns+0xb8/0xc0)
> > [  536.528416]  r9:00000001 r8:00000000 r7:824926dc r6:00000000
> > r5:80df6c2c r4:00000000
> > [  536.536162] [<8035b1dc>] (kernfs_remove_by_name_ns) from
> > [<80b1f56c>] (sysfs_remove_link+0x4c/0x50)
> > [  536.545225]  r6:7f00f02c r5:80df6c2c r4:83306400
> > [  536.549845] [<80b1f520>] (sysfs_remove_link) from [<806f9c8c>]
> > (phy_detach+0xfc/0x11c)
> > [  536.557780]  r5:82492000 r4:83306400
> > [  536.561359] [<806f9b90>] (phy_detach) from [<806f9cf8>]
> > (phy_disconnect+0x4c/0x58)
> > [  536.568943]  r7:824926dc r6:7f00f02c r5:82492580 r4:83306400
> > [  536.574604] [<806f9cac>] (phy_disconnect) from [<7f00a310>]
> > (smsc95xx_disconnect_phy+0x30/0x38 [smsc95xx])
> > [  536.584290]  r5:82492580 r4:82492580
> > [  536.587868] [<7f00a2e0>] (smsc95xx_disconnect_phy [smsc95xx])
> > from [<7f001570>] (usbnet_stop+0x70/0x1a0 [usbnet])
> > [  536.598161]  r5:82492580 r4:82492000
> > [  536.601740] [<7f001500>] (usbnet_stop [usbnet]) from
> > [<808baa70>] (__dev_close_many+0xb4/0x12c)
> > [  536.610466]  r8:83744000 r7:00000000 r6:83744000 r5:83745b74
> > r4:82492000
> > [  536.617170] [<808ba9bc>] (__dev_close_many) from [<808bab78>]
> > (dev_close_many+0x90/0x120)
> > [  536.625365]  r7:00000001 r6:83745b74 r5:83745b8c r4:82492000
> > [  536.631026] [<808baae8>] (dev_close_many) from [<808bf408>]
> > (unregister_netdevice_many+0x15c/0x704)
> > [  536.640094]  r9:00000001 r8:81130b98 r7:83745b74 r6:83745bc4
> > r5:83745b8c r4:82492000
> > [  536.647840] [<808bf2ac>] (unregister_netdevice_many) from
> > [<808bfa50>] (unregister_netdevice_queue+0xa0/0xe8)
> > [  536.657775]  r10:8112bcc0 r9:83306c00 r8:83306c80 r7:8291e420
> > r6:83744000 r5:00000000
> > [  536.665608]  r4:82492000
> > [  536.668143] [<808bf9b0>] (unregister_netdevice_queue) from
> > [<808bfac0>] (unregister_netdev+0x28/0x30)
> > [  536.677381]  r6:7f01003c r5:82492000 r4:82492000
> > [  536.682000] [<808bfa98>] (unregister_netdev) from [<7f000b40>]
> > (usbnet_disconnect+0x64/0xdc [usbnet])
> > [  536.691241]  r5:82492000 r4:82492580
> > [  536.694819] [<7f000adc>] (usbnet_disconnect [usbnet]) from
> > [<8076b958>] (usb_unbind_interface+0x80/0x248)
> > [  536.704406]  r5:7f01003c r4:83306c80
> > [  536.707984] [<8076b8d8>] (usb_unbind_interface) from
> > [<8061765c>] (device_release_driver_internal+0x1c4/0x1cc)
> > [  536.718005]  r10:8112bcc0 r9:80dff1dc r8:83306c80 r7:83744000
> > r6:7f01003c r5:00000000
> > [  536.725838]  r4:8291e420
> > [  536.728373] [<80617498>] (device_release_driver_internal) from
> > [<80617684>] (device_release_driver+0x20/0x24)
> > [  536.738302]  r7:83744000 r6:810d4f4c r5:8291e420 r4:8176ae30
> > [  536.743963] [<80617664>] (device_release_driver) from
> > [<806156cc>] (bus_remove_device+0xf0/0x148)
> > [  536.752858] [<806155dc>] (bus_remove_device) from [<80610018>]
> > (device_del+0x198/0x41c)
> > [  536.760880]  r7:83744000 r6:8116e2e4 r5:8291e464 r4:8291e420
> > [  536.766542] [<8060fe80>] (device_del) from [<80768fe8>]
> > (usb_disable_device+0xcc/0x1e0)
> > [  536.774576]  r10:8112bcc0 r9:80dff1dc r8:00000001 r7:8112bc48
> > r6:8291e400 r5:00000001
> > [  536.782410]  r4:83306c00
> > [  536.784945] [<80768f1c>] (usb_disable_device) from [<80769c30>]
> > (usb_set_configuration+0x514/0x8dc)
> > [  536.794011]  r10:00000000 r9:00000000 r8:832c3600 r7:00000004
> > r6:810d5688 r5:00000000
> > [  536.801844]  r4:83306c00
> > [  536.804379] [<8076971c>] (usb_set_configuration) from
> > [<80775fac>] (usb_generic_driver_disconnect+0x34/0x38)
> > [  536.814236]  r10:832c3610 r9:83745ef8 r8:832c3600 r7:00000004
> > r6:810d5688 r5:83306c00
> > [  536.822069]  r4:83306c00
> > [  536.824605] [<80775f78>] (usb_generic_driver_disconnect) from
> > [<8076b850>] (usb_unbind_device+0x30/0x70)
> > [  536.834100]  r5:83306c00 r4:810d5688
> > [  536.837678] [<8076b820>] (usb_unbind_device) from [<8061765c>]
> > (device_release_driver_internal+0x1c4/0x1cc)
> > [  536.847432]  r5:822fb480 r4:83306c80
> > [  536.851009] [<80617498>] (device_release_driver_internal) from
> > [<806176a8>] (device_driver_detach+0x20/0x24)
> > [  536.860853]  r7:00000004 r6:810d4f4c r5:810d5688 r4:83306c80
> > [  536.866515] [<80617688>] (device_driver_detach) from
> > [<80614d98>] (unbind_store+0x70/0xe4)
> > [  536.874793] [<80614d28>] (unbind_store) from [<80614118>]
> > (drv_attr_store+0x30/0x3c)
> > [  536.882554]  r7:00000000 r6:00000000 r5:83739200 r4:80614d28
> > [  536.888217] [<806140e8>] (drv_attr_store) from [<8035cb68>]
> > (sysfs_kf_write+0x48/0x54)
> > [  536.896154]  r5:83739200 r4:806140e8
> > [  536.899732] [<8035cb20>] (sysfs_kf_write) from [<8035be84>]
> > (kernfs_fop_write_iter+0x11c/0x1d4)
> > [  536.908446]  r5:83739200 r4:00000004
> > [  536.912024] [<8035bd68>] (kernfs_fop_write_iter) from
> > [<802b87fc>] (vfs_write+0x258/0x3e4)
> > [  536.920317]  r10:00000000 r9:83745f58 r8:83744000 r7:00000000
> > r6:00000004 r5:00000000
> > [  536.928151]  r4:82adacc0
> > [  536.930687] [<802b85a4>] (vfs_write) from [<802b8b0c>]
> > (ksys_write+0x74/0xf4)
> > [  536.937842]  r10:00000004 r9:007767a0 r8:83744000 r7:00000000
> > r6:00000000 r5:82adacc0
> > [  536.945676]  r4:82adacc0
> > [  536.948213] [<802b8a98>] (ksys_write) from [<802b8ba4>]
> > (sys_write+0x18/0x1c)
> > [  536.955367]  r10:00000004 r9:83744000 r8:80100244 r7:00000004
> > r6:76f47b58 r5:76fc0350
> > [  536.963200]  r4:00000004
> > [  536.965735] [<802b8b8c>] (sys_write) from [<80100060>]
> > (ret_fast_syscall+0x0/0x48)
> > [  536.973320] Exception stack(0x83745fa8 to 0x83745ff0)
> > [  536.978383] 5fa0:                   00000004 76fc0350 00000001
> > 007767a0 00000004 00000000
> > [  536.986569] 5fc0: 00000004 76fc0350 76f47b58 00000004 76f47c7c
> > 76f48114 00000000 7e87991c
> > [  536.994753] 5fe0: 00000498 7e879908 76e6dce8 76eca2e8
> > [  536.999922] ---[ end trace 9b835d809816b435 ]---
> 
> I am testing this patch on Intel Edison-Arduino with Linux 5.15.1.
> I had reported this issue earlier as
> https://lore.kernel.org/linux-usb/07628a9b-1370-98b7-c1f3-98b9bf8cc38f@gmail.com/
> 
> This patch indeed resolves the above crash on each unplug.
> 
> > The driver should not be connecting and disconnecting the PHY when
> > the
> > device is opened and closed, it should be stopping and starting the
> > PHY. The
> > phy should be connected as part of binding and disconnected during
> > unbinding.
> > 
> > As this results in the PHY not being reset during open, link speed,
> > etc.
> > settings set prior to the link coming up are now not being lost.
> > 
> > It is necessary for phy_stop() to only be called when the phydev
> > still
> > exists (resolving the above stack trace). When unbinding, ".unbind"
> > will be
> > called prior to ".stop", with phy_disconnect() already having
> > called
> > phy_stop() before the phydev becomes inaccessible.
> 
> The patch introduces a new error on each unplug:
> 
> usb 1-1: USB disconnect, device number 2
> usb 1-1.1: USB disconnect, device number 3
> smsc95xx 1-1.1:1.0 eth0: unregister 'smsc95xx' usb-xhci-hcd.1.auto-
> 1.1, 
> smsc95xx USB 2.0 Ethernet
> smsc95xx 1-1.1:1.0 eth0: Link is Down
> smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
> smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
> smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
> smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
> smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
> smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
> smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
> 

Agh! Somehow missed that. I'm looking into it...


> Also as reported earlier, (only) on first plug the more worrying but 
> possibly unrelated crash still happens:
> ------------[ cut here ]------------
> DMA-API: xhci-hcd xhci-hcd.1.auto: cacheline tracking EEXIST, 
> overlapping mappings aren't supported
> WARNING: CPU: 0 PID: 23 at kernel/dma/debug.c:570
> add_dma_entry+0x1d9/0x270
> Modules linked in: rfcomm iptable_nat bnep usb_f_uac2 u_audio 
> snd_sof_nocodec usb_f_mass_storage usb_f_eem u_ether
> spi_pxa2xx_platform 
> dw_dmac usb_f_serial u_serial libcomposite intel_mrfld_pwrbtn 
> snd_sof_pci_intel_tng pwm_lpss_pci intel_mrfld_adc pwm_lpss
> snd_sof_pci 
> snd_sof_intel_ipc snd_sof_intel_atom dw_dmac_pci dw_dmac_core snd_sof
> snd_sof_xtensa_dsp snd_soc_acpi spi_pxa2xx_pci brcmfmac brcmutil 
> hci_uart leds_gpio btbcm ti_ads7950 industrialio_triggered_buffer 
> kfifo_buf tun ledtrig_timer ledtrig_heartbeat mmc_block 
> extcon_intel_mrfld sdhci_pci cqhci sdhci led_class mmc_core 
> intel_soc_pmic_mrfld btrfs libcrc32c xor zstd_compress zlib_deflate
> raid6_pq
> CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 5.15.1-edison-acpi-
> standard #1
> Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 
> 2015.01.21:18.19.48
> Workqueue: usb_hub_wq hub_event
> RIP: 0010:add_dma_entry+0x1d9/0x270
> Code: ff 0f 84 97 00 00 00 4c 8b 67 50 4d 85 e4 75 03 4c 8b 27 e8 39
> ff 
> 52 00 48 89 c6 4c 89 e2 48 c7 c7 f0 ab e7 a7 e8 c7 5c b5 00 <0f> 0b
> 48 
> 85 ed 0f 85 a4 b3 b5 00 8b 05 46 38 9f 01 85 c0 0f 85 df
> RSP: 0000:ffffb047400cfac8 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffff9e25fe217478
> RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9e25fe217470
> RBP: ffff9e25c12ff780 R08: ffffffffa83359a8 R09: 0000000000009ffb
> R10: 00000000ffffe000 R11: 3fffffffffffffff R12: ffff9e25c8a24040
> R13: 0000000000000001 R14: 0000000000000206 R15: 00000000000f8be4
> FS:  0000000000000000(0000) GS:ffff9e25fe200000(0000)
> knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f62c6d586d8 CR3: 0000000002f3c000 CR4: 00000000001006f0
> Call Trace:
>   dma_map_page_attrs+0xfb/0x250
>   ? usb_hcd_link_urb_to_ep+0x14/0xa0
>   usb_hcd_map_urb_for_dma+0x3b1/0x4e0
>   usb_hcd_submit_urb+0x93/0xbb0
>   ? create_prof_cpu_mask+0x20/0x20
>   ? arch_stack_walk+0x73/0xf0
>   ? usb_hcd_link_urb_to_ep+0x14/0xa0
>   ? prepare_transfer+0xff/0x140
>   usb_start_wait_urb+0x60/0x160
>   usb_control_msg+0xda/0x140
>   hub_ext_port_status+0x82/0x100
>   hub_event+0x1b1/0x1830
>   ? hub_activate+0x58c/0x860
>   process_one_work+0x1d4/0x370
>   worker_thread+0x48/0x3d0
>   ? rescuer_thread+0x360/0x360
>   kthread+0x122/0x140
>   ? set_kthread_struct+0x40/0x40
>   ret_from_fork+0x22/0x30
> ---[ end trace da6ffcd9fad23a74 ]---
> DMA-API: Mapped at:
>   debug_dma_map_page+0x60/0xf0
>   dma_map_page_attrs+0xfb/0x250
>   usb_hcd_map_urb_for_dma+0x3b1/0x4e0
>   usb_hcd_submit_urb+0x93/0xbb0
>   usb_start_wait_urb+0x60/0x160
> usb 1-1.1: new high-speed USB device number 3 using xhci-hcd
> usb 1-1.1: New USB device found, idVendor=0424, idProduct=ec00, 
> bcdDevice= 2.00
> usb 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> usb 1-1.1: Product: LAN9514
> usb 1-1.1: Manufacturer: SMSC
> usb 1-1.1: SerialNumber: 00951d0d
> 
> 

I'm not seeing that at all, but I've also been developing and testing
on an ARM based device that has the LAN9500A I'm using built into it.

I have also recently got a LAN9500A devkit which I've tried on my Ryzen
laptop and that's not throwing that error either.

Martyn

> 
> > Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
> > Cc: Steve Glendinning <steve.glendinning@shawell.net>
> > Cc: UNGLinuxDriver@microchip.com
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Jakub Kicinski <kuba@kernel.org>
> > Cc: stable@kernel.org # v5.15
> > ---
> >   drivers/net/usb/smsc95xx.c | 55 ++++++++++++++++++---------------
> > -----
> >   1 file changed, 26 insertions(+), 29 deletions(-)
> > 
> > diff --git a/drivers/net/usb/smsc95xx.c
> > b/drivers/net/usb/smsc95xx.c
> > index 26b1bd8e845b..f91dabd65ecd 100644
> > --- a/drivers/net/usb/smsc95xx.c
> > +++ b/drivers/net/usb/smsc95xx.c
> > @@ -1049,6 +1049,14 @@ static const struct net_device_ops
> > smsc95xx_netdev_ops = {
> >         .ndo_set_features       = smsc95xx_set_features,
> >   };
> >   
> > +static void smsc95xx_handle_link_change(struct net_device *net)
> > +{
> > +       struct usbnet *dev = netdev_priv(net);
> > +
> > +       phy_print_status(net->phydev);
> > +       usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
> > +}
> > +
> >   static int smsc95xx_bind(struct usbnet *dev, struct usb_interface
> > *intf)
> >   {
> >         struct smsc95xx_priv *pdata;
> > @@ -1153,6 +1161,17 @@ static int smsc95xx_bind(struct usbnet *dev,
> > struct usb_interface *intf)
> >         dev->net->min_mtu = ETH_MIN_MTU;
> >         dev->net->max_mtu = ETH_DATA_LEN;
> >         dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
> > +
> > +       ret = phy_connect_direct(dev->net, pdata->phydev,
> > +                                &smsc95xx_handle_link_change,
> > +                                PHY_INTERFACE_MODE_MII);
> > +       if (ret) {
> > +               netdev_err(dev->net, "can't attach PHY to %s\n",
> > pdata->mdiobus->id);
> > +               goto unregister_mdio;
> > +       }
> > +
> > +       phy_attached_info(dev->net->phydev);
> > +
> >         return 0;
> >   
> >   unregister_mdio:
> > @@ -1170,47 +1189,25 @@ static void smsc95xx_unbind(struct usbnet
> > *dev, struct usb_interface *intf)
> >   {
> >         struct smsc95xx_priv *pdata = dev->driver_priv;
> >   
> > +       phy_disconnect(dev->net->phydev);
> >         mdiobus_unregister(pdata->mdiobus);
> >         mdiobus_free(pdata->mdiobus);
> >         netif_dbg(dev, ifdown, dev->net, "free pdata\n");
> >         kfree(pdata);
> >   }
> >   
> > -static void smsc95xx_handle_link_change(struct net_device *net)
> > -{
> > -       struct usbnet *dev = netdev_priv(net);
> > -
> > -       phy_print_status(net->phydev);
> > -       usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
> > -}
> > -
> >   static int smsc95xx_start_phy(struct usbnet *dev)
> >   {
> > -       struct smsc95xx_priv *pdata = dev->driver_priv;
> > -       struct net_device *net = dev->net;
> > -       int ret;
> > +       phy_start(dev->net->phydev);
> >   
> > -       ret = smsc95xx_reset(dev);
> > -       if (ret < 0)
> > -               return ret;
> > -
> > -       ret = phy_connect_direct(net, pdata->phydev,
> > -                                &smsc95xx_handle_link_change,
> > -                                PHY_INTERFACE_MODE_MII);
> > -       if (ret) {
> > -               netdev_err(net, "can't attach PHY to %s\n", pdata-
> > >mdiobus->id);
> > -               return ret;
> > -       }
> > -
> > -       phy_attached_info(net->phydev);
> > -       phy_start(net->phydev);
> >         return 0;
> >   }
> >   
> > -static int smsc95xx_disconnect_phy(struct usbnet *dev)
> > +static int smsc95xx_stop(struct usbnet *dev)
> >   {
> > -       phy_stop(dev->net->phydev);
> > -       phy_disconnect(dev->net->phydev);
> > +       if (dev->net->phydev)
> > +               phy_stop(dev->net->phydev);
> > +
> >         return 0;
> >   }
> >   
> > @@ -1965,7 +1962,7 @@ static const struct driver_info smsc95xx_info
> > = {
> >         .unbind         = smsc95xx_unbind,
> >         .link_reset     = smsc95xx_link_reset,
> >         .reset          = smsc95xx_start_phy,
> > -       .stop           = smsc95xx_disconnect_phy,
> > +       .stop           = smsc95xx_stop,
> >         .rx_fixup       = smsc95xx_rx_fixup,
> >         .tx_fixup       = smsc95xx_tx_fixup,
> >         .status         = smsc95xx_status,
> > 
> 


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] net: usb: Correct PHY handling of smsc95xx
       [not found]     ` <6a06e3b7-df08-6ec0-6e74-95c21fa43f38@gmail.com>
@ 2021-11-30 18:52       ` Martyn Welch
  2021-11-30 21:47         ` Ferry Toth
  0 siblings, 1 reply; 8+ messages in thread
From: Martyn Welch @ 2021-11-30 18:52 UTC (permalink / raw)
  To: Ferry Toth, netdev
  Cc: linux-usb, linux-kernel, kernel, Steve Glendinning,
	UNGLinuxDriver, David S. Miller, Jakub Kicinski, stable

On Mon, 2021-11-29 at 15:16 +0100, Ferry Toth wrote:
> Hi,
> Op 29-11-2021 om 13:08 schreef Martyn Welch:
>  
> > On Sat, 2021-11-27 at 18:48 +0100, Ferry Toth wrote:
> >  
> > > 
> > > The patch introduces a new error on each unplug:
> > > 
> > > usb 1-1: USB disconnect, device number 2
> > > usb 1-1.1: USB disconnect, device number 3
> > > smsc95xx 1-1.1:1.0 eth0: unregister 'smsc95xx' usb-xhci-hcd.1.auto-
> > > 1.1, 
> > > smsc95xx USB 2.0 Ethernet
> > > smsc95xx 1-1.1:1.0 eth0: Link is Down
> > > smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
> > > smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
> > > smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
> > > smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
> > > smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
> > > smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
> > > smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
> > > 
> > Agh! Somehow missed that. I'm looking into it...
>  That would be great!
>  

They appear as a result of phy_disconnect() being called in unbind()
when the hardware has already been disconnected (which is kinda likely
to physically be the case with USB devices...). The PHY is not going to
be accessible, but such calls *are* needed for instances where we are
unbinding without the device having been physically removed and want to
put the device in a suitable state. Failing with -ENODEV (as it
currently does) seems to be the right thing to do.

I wonder whether removing some of these error messages might be an
option? It appears that some of them are present in other drivers, but
I don't know whether such messages get displayed when that hardware is
unplugged too or whether I'm missing something that protects against
that.

> > 
> >  
> > > Also as reported earlier, (only) on first plug the more worrying
> > > but 
> > > possibly unrelated crash still happens:
> > > ------------[ cut here ]------------
> > > DMA-API: xhci-hcd xhci-hcd.1.auto: cacheline tracking EEXIST, 
> > > overlapping mappings aren't supported
> > > WARNING: CPU: 0 PID: 23 at kernel/dma/debug.c:570
> > > add_dma_entry+0x1d9/0x270
> > > Modules linked in: rfcomm iptable_nat bnep usb_f_uac2 u_audio 
> > > snd_sof_nocodec usb_f_mass_storage usb_f_eem u_ether
> > > spi_pxa2xx_platform 
> > > dw_dmac usb_f_serial u_serial libcomposite intel_mrfld_pwrbtn 
> > > snd_sof_pci_intel_tng pwm_lpss_pci intel_mrfld_adc pwm_lpss
> > > snd_sof_pci 
> > > snd_sof_intel_ipc snd_sof_intel_atom dw_dmac_pci dw_dmac_core
> > > snd_sof
> > > snd_sof_xtensa_dsp snd_soc_acpi spi_pxa2xx_pci brcmfmac brcmutil 
> > > hci_uart leds_gpio btbcm ti_ads7950 industrialio_triggered_buffer
> > > kfifo_buf tun ledtrig_timer ledtrig_heartbeat mmc_block 
> > > extcon_intel_mrfld sdhci_pci cqhci sdhci led_class mmc_core 
> > > intel_soc_pmic_mrfld btrfs libcrc32c xor zstd_compress zlib_deflate
> > > raid6_pq
> > > CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 5.15.1-edison-acpi-
> > > standard #1
> > > Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 
> > > 2015.01.21:18.19.48
> > > Workqueue: usb_hub_wq hub_event
> > > RIP: 0010:add_dma_entry+0x1d9/0x270
> > > Code: ff 0f 84 97 00 00 00 4c 8b 67 50 4d 85 e4 75 03 4c 8b 27 e8
> > > 39
> > > ff 
> > > 52 00 48 89 c6 4c 89 e2 48 c7 c7 f0 ab e7 a7 e8 c7 5c b5 00 <0f> 0b
> > > 48 
> > > 85 ed 0f 85 a4 b3 b5 00 8b 05 46 38 9f 01 85 c0 0f 85 df
> > > RSP: 0000:ffffb047400cfac8 EFLAGS: 00010282
> > > RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffff9e25fe217478
> > > RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9e25fe217470
> > > RBP: ffff9e25c12ff780 R08: ffffffffa83359a8 R09: 0000000000009ffb
> > > R10: 00000000ffffe000 R11: 3fffffffffffffff R12: ffff9e25c8a24040
> > > R13: 0000000000000001 R14: 0000000000000206 R15: 00000000000f8be4
> > > FS:  0000000000000000(0000) GS:ffff9e25fe200000(0000)
> > > knlGS:0000000000000000
> > > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > CR2: 00007f62c6d586d8 CR3: 0000000002f3c000 CR4: 00000000001006f0
> > > Call Trace:
> > >   dma_map_page_attrs+0xfb/0x250
> > >   ? usb_hcd_link_urb_to_ep+0x14/0xa0
> > >   usb_hcd_map_urb_for_dma+0x3b1/0x4e0
> > >   usb_hcd_submit_urb+0x93/0xbb0
> > >   ? create_prof_cpu_mask+0x20/0x20
> > >   ? arch_stack_walk+0x73/0xf0
> > >   ? usb_hcd_link_urb_to_ep+0x14/0xa0
> > >   ? prepare_transfer+0xff/0x140
> > >   usb_start_wait_urb+0x60/0x160
> > >   usb_control_msg+0xda/0x140
> > >   hub_ext_port_status+0x82/0x100
> > >   hub_event+0x1b1/0x1830
> > >   ? hub_activate+0x58c/0x860
> > >   process_one_work+0x1d4/0x370
> > >   worker_thread+0x48/0x3d0
> > >   ? rescuer_thread+0x360/0x360
> > >   kthread+0x122/0x140
> > >   ? set_kthread_struct+0x40/0x40
> > >   ret_from_fork+0x22/0x30
> > > ---[ end trace da6ffcd9fad23a74 ]---
> > > DMA-API: Mapped at:
> > >   debug_dma_map_page+0x60/0xf0
> > >   dma_map_page_attrs+0xfb/0x250
> > >   usb_hcd_map_urb_for_dma+0x3b1/0x4e0
> > >   usb_hcd_submit_urb+0x93/0xbb0
> > >   usb_start_wait_urb+0x60/0x160
> > > usb 1-1.1: new high-speed USB device number 3 using xhci-hcd
> > > usb 1-1.1: New USB device found, idVendor=0424, idProduct=ec00, 
> > > bcdDevice= 2.00
> > > usb 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> > > usb 1-1.1: Product: LAN9514
> > > usb 1-1.1: Manufacturer: SMSC
> > > usb 1-1.1: SerialNumber: 00951d0d
> > > 
> > > 
> > I'm not seeing that at all, but I've also been developing and testing
> > on an ARM based device that has the LAN9500A I'm using built into it.
> > 
> > I have also recently got a LAN9500A devkit which I've tried on my
> > Ryzen
> > laptop and that's not throwing that error either.
> > 
> > Martyn
> Yes I am using the LAN9514 Evaluation board (EVB9514). Plugging the
> board into my desktop with 5.15 Ubuntu PPA kernel I also don't see this
> crash.
> OTOH I'm building vanilla kernel so no idea why this happens. It might
> be that I have CONFIG_DMA_API_DEBUG and Ubuntu not.
>  

I suspect this is probably unrelated (directly) to the driver then.

Martyn

> 

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] net: usb: Correct PHY handling of smsc95xx
  2021-11-30 18:52       ` Martyn Welch
@ 2021-11-30 21:47         ` Ferry Toth
  2021-12-01 10:56           ` Martyn Welch
  0 siblings, 1 reply; 8+ messages in thread
From: Ferry Toth @ 2021-11-30 21:47 UTC (permalink / raw)
  To: Martyn Welch, netdev
  Cc: linux-usb, linux-kernel, kernel, Steve Glendinning,
	UNGLinuxDriver, David S. Miller, Jakub Kicinski, stable

Op 30-11-2021 om 19:52 schreef Martyn Welch:
> On Mon, 2021-11-29 at 15:16 +0100, Ferry Toth wrote:
>> Hi,
>> Op 29-11-2021 om 13:08 schreef Martyn Welch:
>>   
>>> On Sat, 2021-11-27 at 18:48 +0100, Ferry Toth wrote:
>>>   
>>>>
>>>> The patch introduces a new error on each unplug:
>>>>
>>>> usb 1-1: USB disconnect, device number 2
>>>> usb 1-1.1: USB disconnect, device number 3
>>>> smsc95xx 1-1.1:1.0 eth0: unregister 'smsc95xx' usb-xhci-hcd.1.auto-
>>>> 1.1,
>>>> smsc95xx USB 2.0 Ethernet
>>>> smsc95xx 1-1.1:1.0 eth0: Link is Down
>>>> smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
>>>> smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
>>>> smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
>>>> smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
>>>> smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
>>>> smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
>>>> smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
>>>>
>>> Agh! Somehow missed that. I'm looking into it...
>>   That would be great!
>>   
> 
> They appear as a result of phy_disconnect() being called in unbind()
> when the hardware has already been disconnected (which is kinda likely
> to physically be the case with USB devices...). The PHY is not going to
> be accessible, but such calls *are* needed for instances where we are
> unbinding without the device having been physically removed and want to
> put the device in a suitable state. Failing with -ENODEV (as it
> currently does) seems to be the right thing to do.
> 
> I wonder whether removing some of these error messages might be an
> option? It appears that some of them are present in other drivers, but
> I don't know whether such messages get displayed when that hardware is
> unplugged too or whether I'm missing something that protects against
> that.
I just retried 5.10.63 and found it did not yet have the crash that you 
fix here. But it did have the above Error reading MII_ACCESS. So 
apparently this is more of an older annoyance since smsc95xx v2.00?
>>>
>>>   
>>>> Also as reported earlier, (only) on first plug the more worrying
>>>> but
>>>> possibly unrelated crash still happens:
>>>> ------------[ cut here ]------------
>>>> DMA-API: xhci-hcd xhci-hcd.1.auto: cacheline tracking EEXIST,
>>>> overlapping mappings aren't supported
>>>> WARNING: CPU: 0 PID: 23 at kernel/dma/debug.c:570
>>>> add_dma_entry+0x1d9/0x270
>>>> Modules linked in: rfcomm iptable_nat bnep usb_f_uac2 u_audio
>>>> snd_sof_nocodec usb_f_mass_storage usb_f_eem u_ether
>>>> spi_pxa2xx_platform
>>>> dw_dmac usb_f_serial u_serial libcomposite intel_mrfld_pwrbtn
>>>> snd_sof_pci_intel_tng pwm_lpss_pci intel_mrfld_adc pwm_lpss
>>>> snd_sof_pci
>>>> snd_sof_intel_ipc snd_sof_intel_atom dw_dmac_pci dw_dmac_core
>>>> snd_sof
>>>> snd_sof_xtensa_dsp snd_soc_acpi spi_pxa2xx_pci brcmfmac brcmutil
>>>> hci_uart leds_gpio btbcm ti_ads7950 industrialio_triggered_buffer
>>>> kfifo_buf tun ledtrig_timer ledtrig_heartbeat mmc_block
>>>> extcon_intel_mrfld sdhci_pci cqhci sdhci led_class mmc_core
>>>> intel_soc_pmic_mrfld btrfs libcrc32c xor zstd_compress zlib_deflate
>>>> raid6_pq
>>>> CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 5.15.1-edison-acpi-
>>>> standard #1
>>>> Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542
>>>> 2015.01.21:18.19.48
>>>> Workqueue: usb_hub_wq hub_event
>>>> RIP: 0010:add_dma_entry+0x1d9/0x270
>>>> Code: ff 0f 84 97 00 00 00 4c 8b 67 50 4d 85 e4 75 03 4c 8b 27 e8
>>>> 39
>>>> ff
>>>> 52 00 48 89 c6 4c 89 e2 48 c7 c7 f0 ab e7 a7 e8 c7 5c b5 00 <0f> 0b
>>>> 48
>>>> 85 ed 0f 85 a4 b3 b5 00 8b 05 46 38 9f 01 85 c0 0f 85 df
>>>> RSP: 0000:ffffb047400cfac8 EFLAGS: 00010282
>>>> RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffff9e25fe217478
>>>> RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9e25fe217470
>>>> RBP: ffff9e25c12ff780 R08: ffffffffa83359a8 R09: 0000000000009ffb
>>>> R10: 00000000ffffe000 R11: 3fffffffffffffff R12: ffff9e25c8a24040
>>>> R13: 0000000000000001 R14: 0000000000000206 R15: 00000000000f8be4
>>>> FS:  0000000000000000(0000) GS:ffff9e25fe200000(0000)
>>>> knlGS:0000000000000000
>>>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>> CR2: 00007f62c6d586d8 CR3: 0000000002f3c000 CR4: 00000000001006f0
>>>> Call Trace:
>>>>    dma_map_page_attrs+0xfb/0x250
>>>>    ? usb_hcd_link_urb_to_ep+0x14/0xa0
>>>>    usb_hcd_map_urb_for_dma+0x3b1/0x4e0
>>>>    usb_hcd_submit_urb+0x93/0xbb0
>>>>    ? create_prof_cpu_mask+0x20/0x20
>>>>    ? arch_stack_walk+0x73/0xf0
>>>>    ? usb_hcd_link_urb_to_ep+0x14/0xa0
>>>>    ? prepare_transfer+0xff/0x140
>>>>    usb_start_wait_urb+0x60/0x160
>>>>    usb_control_msg+0xda/0x140
>>>>    hub_ext_port_status+0x82/0x100
>>>>    hub_event+0x1b1/0x1830
>>>>    ? hub_activate+0x58c/0x860
>>>>    process_one_work+0x1d4/0x370
>>>>    worker_thread+0x48/0x3d0
>>>>    ? rescuer_thread+0x360/0x360
>>>>    kthread+0x122/0x140
>>>>    ? set_kthread_struct+0x40/0x40
>>>>    ret_from_fork+0x22/0x30
>>>> ---[ end trace da6ffcd9fad23a74 ]---
>>>> DMA-API: Mapped at:
>>>>    debug_dma_map_page+0x60/0xf0
>>>>    dma_map_page_attrs+0xfb/0x250
>>>>    usb_hcd_map_urb_for_dma+0x3b1/0x4e0
>>>>    usb_hcd_submit_urb+0x93/0xbb0
>>>>    usb_start_wait_urb+0x60/0x160
>>>> usb 1-1.1: new high-speed USB device number 3 using xhci-hcd
>>>> usb 1-1.1: New USB device found, idVendor=0424, idProduct=ec00,
>>>> bcdDevice= 2.00
>>>> usb 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
>>>> usb 1-1.1: Product: LAN9514
>>>> usb 1-1.1: Manufacturer: SMSC
>>>> usb 1-1.1: SerialNumber: 00951d0d
>>>>
>>>>
>>> I'm not seeing that at all, but I've also been developing and testing
>>> on an ARM based device that has the LAN9500A I'm using built into it.
>>>
>>> I have also recently got a LAN9500A devkit which I've tried on my
>>> Ryzen
>>> laptop and that's not throwing that error either.
>>>
>>> Martyn
>> Yes I am using the LAN9514 Evaluation board (EVB9514). Plugging the
>> board into my desktop with 5.15 Ubuntu PPA kernel I also don't see this
>> crash.
>> OTOH I'm building vanilla kernel so no idea why this happens. It might
>> be that I have CONFIG_DMA_API_DEBUG and Ubuntu not.
>>   
> 
> I suspect this is probably unrelated (directly) to the driver then.

Maybe not related to this driver but possibly an old bug in hub.c which 
only surfaces now due to patch "[PATCH] dma debug: report -EEXIST errors 
in add_dma_entry"? And only shows when CONFIG_DMA_API_DEBUG is set?

Ferry

> Martyn
> 
>>


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] net: usb: Correct PHY handling of smsc95xx
  2021-11-30 21:47         ` Ferry Toth
@ 2021-12-01 10:56           ` Martyn Welch
  2021-12-01 22:24             ` Ferry Toth
  0 siblings, 1 reply; 8+ messages in thread
From: Martyn Welch @ 2021-12-01 10:56 UTC (permalink / raw)
  To: Ferry Toth, netdev
  Cc: linux-usb, linux-kernel, kernel, Steve Glendinning,
	UNGLinuxDriver, David S. Miller, Jakub Kicinski, stable

On Tue, 2021-11-30 at 22:47 +0100, Ferry Toth wrote:
> Op 30-11-2021 om 19:52 schreef Martyn Welch:
> > On Mon, 2021-11-29 at 15:16 +0100, Ferry Toth wrote:
> > > Hi,
> > > Op 29-11-2021 om 13:08 schreef Martyn Welch:
> > >   
> > > > On Sat, 2021-11-27 at 18:48 +0100, Ferry Toth wrote:
> > > >   
> > > > > 
> > > > > The patch introduces a new error on each unplug:
> > > > > 
> > > > > usb 1-1: USB disconnect, device number 2
> > > > > usb 1-1.1: USB disconnect, device number 3
> > > > > smsc95xx 1-1.1:1.0 eth0: unregister 'smsc95xx' usb-xhci-
> > > > > hcd.1.auto-
> > > > > 1.1,
> > > > > smsc95xx USB 2.0 Ethernet
> > > > > smsc95xx 1-1.1:1.0 eth0: Link is Down
> > > > > smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -
> > > > > 19
> > > > > smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
> > > > > smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
> > > > > smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -
> > > > > 19
> > > > > smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
> > > > > smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
> > > > > smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote
> > > > > wakeup
> > > > > 
> > > > Agh! Somehow missed that. I'm looking into it...
> > >   That would be great!
> > >   
> > 
> > They appear as a result of phy_disconnect() being called in unbind()
> > when the hardware has already been disconnected (which is kinda
> > likely
> > to physically be the case with USB devices...). The PHY is not going
> > to
> > be accessible, but such calls *are* needed for instances where we are
> > unbinding without the device having been physically removed and want
> > to
> > put the device in a suitable state. Failing with -ENODEV (as it
> > currently does) seems to be the right thing to do.
> > 
> > I wonder whether removing some of these error messages might be an
> > option? It appears that some of them are present in other drivers,
> > but
> > I don't know whether such messages get displayed when that hardware
> > is
> > unplugged too or whether I'm missing something that protects against
> > that.
> I just retried 5.10.63 and found it did not yet have the crash that you
> fix here. But it did have the above Error reading MII_ACCESS. So 
> apparently this is more of an older annoyance since smsc95xx v2.00?

That's an interesting observation. Trying the v4.19 stable branch I see
that these errors aren't generated, however it seems that the driver at
that point may not be making any attempt to stop the PHY when the
driver is unbound/disconnected, which explains the lack of errors.

> > > > 
> > > >   
> > > > > Also as reported earlier, (only) on first plug the more
> > > > > worrying
> > > > > but
> > > > > possibly unrelated crash still happens:
> > > > > ------------[ cut here ]------------
> > > > > DMA-API: xhci-hcd xhci-hcd.1.auto: cacheline tracking EEXIST,
> > > > > overlapping mappings aren't supported
> > > > > WARNING: CPU: 0 PID: 23 at kernel/dma/debug.c:570
> > > > > add_dma_entry+0x1d9/0x270
> > > > > Modules linked in: rfcomm iptable_nat bnep usb_f_uac2 u_audio
> > > > > snd_sof_nocodec usb_f_mass_storage usb_f_eem u_ether
> > > > > spi_pxa2xx_platform
> > > > > dw_dmac usb_f_serial u_serial libcomposite intel_mrfld_pwrbtn
> > > > > snd_sof_pci_intel_tng pwm_lpss_pci intel_mrfld_adc pwm_lpss
> > > > > snd_sof_pci
> > > > > snd_sof_intel_ipc snd_sof_intel_atom dw_dmac_pci dw_dmac_core
> > > > > snd_sof
> > > > > snd_sof_xtensa_dsp snd_soc_acpi spi_pxa2xx_pci brcmfmac
> > > > > brcmutil
> > > > > hci_uart leds_gpio btbcm ti_ads7950
> > > > > industrialio_triggered_buffer
> > > > > kfifo_buf tun ledtrig_timer ledtrig_heartbeat mmc_block
> > > > > extcon_intel_mrfld sdhci_pci cqhci sdhci led_class mmc_core
> > > > > intel_soc_pmic_mrfld btrfs libcrc32c xor zstd_compress
> > > > > zlib_deflate
> > > > > raid6_pq
> > > > > CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 5.15.1-edison-
> > > > > acpi-
> > > > > standard #1
> > > > > Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS
> > > > > 542
> > > > > 2015.01.21:18.19.48
> > > > > Workqueue: usb_hub_wq hub_event
> > > > > RIP: 0010:add_dma_entry+0x1d9/0x270
> > > > > Code: ff 0f 84 97 00 00 00 4c 8b 67 50 4d 85 e4 75 03 4c 8b
> > > > > 27 e8
> > > > > 39
> > > > > ff
> > > > > 52 00 48 89 c6 4c 89 e2 48 c7 c7 f0 ab e7 a7 e8 c7 5c b5 00
> > > > > <0f> 0b
> > > > > 48
> > > > > 85 ed 0f 85 a4 b3 b5 00 8b 05 46 38 9f 01 85 c0 0f 85 df
> > > > > RSP: 0000:ffffb047400cfac8 EFLAGS: 00010282
> > > > > RAX: 0000000000000000 RBX: 00000000ffffffff RCX:
> > > > > ffff9e25fe217478
> > > > > RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI:
> > > > > ffff9e25fe217470
> > > > > RBP: ffff9e25c12ff780 R08: ffffffffa83359a8 R09:
> > > > > 0000000000009ffb
> > > > > R10: 00000000ffffe000 R11: 3fffffffffffffff R12:
> > > > > ffff9e25c8a24040
> > > > > R13: 0000000000000001 R14: 0000000000000206 R15:
> > > > > 00000000000f8be4
> > > > > FS:  0000000000000000(0000) GS:ffff9e25fe200000(0000)
> > > > > knlGS:0000000000000000
> > > > > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > > > CR2: 00007f62c6d586d8 CR3: 0000000002f3c000 CR4:
> > > > > 00000000001006f0
> > > > > Call Trace:
> > > > >    dma_map_page_attrs+0xfb/0x250
> > > > >    ? usb_hcd_link_urb_to_ep+0x14/0xa0
> > > > >    usb_hcd_map_urb_for_dma+0x3b1/0x4e0
> > > > >    usb_hcd_submit_urb+0x93/0xbb0
> > > > >    ? create_prof_cpu_mask+0x20/0x20
> > > > >    ? arch_stack_walk+0x73/0xf0
> > > > >    ? usb_hcd_link_urb_to_ep+0x14/0xa0
> > > > >    ? prepare_transfer+0xff/0x140
> > > > >    usb_start_wait_urb+0x60/0x160
> > > > >    usb_control_msg+0xda/0x140
> > > > >    hub_ext_port_status+0x82/0x100
> > > > >    hub_event+0x1b1/0x1830
> > > > >    ? hub_activate+0x58c/0x860
> > > > >    process_one_work+0x1d4/0x370
> > > > >    worker_thread+0x48/0x3d0
> > > > >    ? rescuer_thread+0x360/0x360
> > > > >    kthread+0x122/0x140
> > > > >    ? set_kthread_struct+0x40/0x40
> > > > >    ret_from_fork+0x22/0x30
> > > > > ---[ end trace da6ffcd9fad23a74 ]---
> > > > > DMA-API: Mapped at:
> > > > >    debug_dma_map_page+0x60/0xf0
> > > > >    dma_map_page_attrs+0xfb/0x250
> > > > >    usb_hcd_map_urb_for_dma+0x3b1/0x4e0
> > > > >    usb_hcd_submit_urb+0x93/0xbb0
> > > > >    usb_start_wait_urb+0x60/0x160
> > > > > usb 1-1.1: new high-speed USB device number 3 using xhci-hcd
> > > > > usb 1-1.1: New USB device found, idVendor=0424,
> > > > > idProduct=ec00,
> > > > > bcdDevice= 2.00
> > > > > usb 1-1.1: New USB device strings: Mfr=1, Product=2,
> > > > > SerialNumber=3
> > > > > usb 1-1.1: Product: LAN9514
> > > > > usb 1-1.1: Manufacturer: SMSC
> > > > > usb 1-1.1: SerialNumber: 00951d0d
> > > > > 
> > > > > 
> > > > I'm not seeing that at all, but I've also been developing and
> > > > testing
> > > > on an ARM based device that has the LAN9500A I'm using built
> > > > into it.
> > > > 
> > > > I have also recently got a LAN9500A devkit which I've tried on
> > > > my
> > > > Ryzen
> > > > laptop and that's not throwing that error either.
> > > > 
> > > > Martyn
> > > Yes I am using the LAN9514 Evaluation board (EVB9514). Plugging
> > > the
> > > board into my desktop with 5.15 Ubuntu PPA kernel I also don't
> > > see this
> > > crash.
> > > OTOH I'm building vanilla kernel so no idea why this happens. It
> > > might
> > > be that I have CONFIG_DMA_API_DEBUG and Ubuntu not.
> > >   
> > 
> > I suspect this is probably unrelated (directly) to the driver then.
> 
> Maybe not related to this driver but possibly an old bug in hub.c
> which 
> only surfaces now due to patch "[PATCH] dma debug: report -EEXIST
> errors 
> in add_dma_entry"? And only shows when CONFIG_DMA_API_DEBUG is set?
> 
> Ferry
> 
> > Martyn
> > 
> > > 
> 


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] net: usb: Correct PHY handling of smsc95xx
  2021-12-01 10:56           ` Martyn Welch
@ 2021-12-01 22:24             ` Ferry Toth
  0 siblings, 0 replies; 8+ messages in thread
From: Ferry Toth @ 2021-12-01 22:24 UTC (permalink / raw)
  To: Martyn Welch, netdev
  Cc: linux-usb, linux-kernel, kernel, Steve Glendinning,
	UNGLinuxDriver, David S. Miller, Jakub Kicinski, stable

Op 01-12-2021 om 11:56 schreef Martyn Welch:
> On Tue, 2021-11-30 at 22:47 +0100, Ferry Toth wrote:
>> Op 30-11-2021 om 19:52 schreef Martyn Welch:
>>> On Mon, 2021-11-29 at 15:16 +0100, Ferry Toth wrote:
>>>> Hi,
>>>> Op 29-11-2021 om 13:08 schreef Martyn Welch:
>>>>    
>>>>> On Sat, 2021-11-27 at 18:48 +0100, Ferry Toth wrote:
>>>>>    
>>>>>>
>>>>>> The patch introduces a new error on each unplug:
>>>>>>
>>>>>> usb 1-1: USB disconnect, device number 2
>>>>>> usb 1-1.1: USB disconnect, device number 3
>>>>>> smsc95xx 1-1.1:1.0 eth0: unregister 'smsc95xx' usb-xhci-
>>>>>> hcd.1.auto-
>>>>>> 1.1,
>>>>>> smsc95xx USB 2.0 Ethernet
>>>>>> smsc95xx 1-1.1:1.0 eth0: Link is Down
>>>>>> smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -
>>>>>> 19
>>>>>> smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
>>>>>> smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
>>>>>> smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -
>>>>>> 19
>>>>>> smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
>>>>>> smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
>>>>>> smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote
>>>>>> wakeup
>>>>>>
>>>>> Agh! Somehow missed that. I'm looking into it...
>>>>    That would be great!
>>>>    
>>>
>>> They appear as a result of phy_disconnect() being called in unbind()
>>> when the hardware has already been disconnected (which is kinda
>>> likely
>>> to physically be the case with USB devices...). The PHY is not going
>>> to
>>> be accessible, but such calls *are* needed for instances where we are
>>> unbinding without the device having been physically removed and want
>>> to
>>> put the device in a suitable state. Failing with -ENODEV (as it
>>> currently does) seems to be the right thing to do.
>>>
>>> I wonder whether removing some of these error messages might be an
>>> option? It appears that some of them are present in other drivers,
>>> but
>>> I don't know whether such messages get displayed when that hardware
>>> is
>>> unplugged too or whether I'm missing something that protects against
>>> that.
>> I just retried 5.10.63 and found it did not yet have the crash that you
>> fix here. But it did have the above Error reading MII_ACCESS. So
>> apparently this is more of an older annoyance since smsc95xx v2.00?
> 
> That's an interesting observation. Trying the v4.19 stable branch I see
> that these errors aren't generated, however it seems that the driver at
> that point may not be making any attempt to stop the PHY when the
> driver is unbound/disconnected, which explains the lack of errors.

If I'm not mistaken v2.0.0 introduced by "smsc95xx: add phylib support" 
in 5.10.0. Version before that was 1.0.6.

>>>>>
>>>>>    
>>>>>> Also as reported earlier, (only) on first plug the more
>>>>>> worrying
>>>>>> but
>>>>>> possibly unrelated crash still happens:
>>>>>> ------------[ cut here ]------------
>>>>>> DMA-API: xhci-hcd xhci-hcd.1.auto: cacheline tracking EEXIST,
>>>>>> overlapping mappings aren't supported
>>>>>> WARNING: CPU: 0 PID: 23 at kernel/dma/debug.c:570
>>>>>> add_dma_entry+0x1d9/0x270
>>>>>> Modules linked in: rfcomm iptable_nat bnep usb_f_uac2 u_audio
>>>>>> snd_sof_nocodec usb_f_mass_storage usb_f_eem u_ether
>>>>>> spi_pxa2xx_platform
>>>>>> dw_dmac usb_f_serial u_serial libcomposite intel_mrfld_pwrbtn
>>>>>> snd_sof_pci_intel_tng pwm_lpss_pci intel_mrfld_adc pwm_lpss
>>>>>> snd_sof_pci
>>>>>> snd_sof_intel_ipc snd_sof_intel_atom dw_dmac_pci dw_dmac_core
>>>>>> snd_sof
>>>>>> snd_sof_xtensa_dsp snd_soc_acpi spi_pxa2xx_pci brcmfmac
>>>>>> brcmutil
>>>>>> hci_uart leds_gpio btbcm ti_ads7950
>>>>>> industrialio_triggered_buffer
>>>>>> kfifo_buf tun ledtrig_timer ledtrig_heartbeat mmc_block
>>>>>> extcon_intel_mrfld sdhci_pci cqhci sdhci led_class mmc_core
>>>>>> intel_soc_pmic_mrfld btrfs libcrc32c xor zstd_compress
>>>>>> zlib_deflate
>>>>>> raid6_pq
>>>>>> CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 5.15.1-edison-
>>>>>> acpi-
>>>>>> standard #1
>>>>>> Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS
>>>>>> 542
>>>>>> 2015.01.21:18.19.48
>>>>>> Workqueue: usb_hub_wq hub_event
>>>>>> RIP: 0010:add_dma_entry+0x1d9/0x270
>>>>>> Code: ff 0f 84 97 00 00 00 4c 8b 67 50 4d 85 e4 75 03 4c 8b
>>>>>> 27 e8
>>>>>> 39
>>>>>> ff
>>>>>> 52 00 48 89 c6 4c 89 e2 48 c7 c7 f0 ab e7 a7 e8 c7 5c b5 00
>>>>>> <0f> 0b
>>>>>> 48
>>>>>> 85 ed 0f 85 a4 b3 b5 00 8b 05 46 38 9f 01 85 c0 0f 85 df
>>>>>> RSP: 0000:ffffb047400cfac8 EFLAGS: 00010282
>>>>>> RAX: 0000000000000000 RBX: 00000000ffffffff RCX:
>>>>>> ffff9e25fe217478
>>>>>> RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI:
>>>>>> ffff9e25fe217470
>>>>>> RBP: ffff9e25c12ff780 R08: ffffffffa83359a8 R09:
>>>>>> 0000000000009ffb
>>>>>> R10: 00000000ffffe000 R11: 3fffffffffffffff R12:
>>>>>> ffff9e25c8a24040
>>>>>> R13: 0000000000000001 R14: 0000000000000206 R15:
>>>>>> 00000000000f8be4
>>>>>> FS:  0000000000000000(0000) GS:ffff9e25fe200000(0000)
>>>>>> knlGS:0000000000000000
>>>>>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>>>> CR2: 00007f62c6d586d8 CR3: 0000000002f3c000 CR4:
>>>>>> 00000000001006f0
>>>>>> Call Trace:
>>>>>>     dma_map_page_attrs+0xfb/0x250
>>>>>>     ? usb_hcd_link_urb_to_ep+0x14/0xa0
>>>>>>     usb_hcd_map_urb_for_dma+0x3b1/0x4e0
>>>>>>     usb_hcd_submit_urb+0x93/0xbb0
>>>>>>     ? create_prof_cpu_mask+0x20/0x20
>>>>>>     ? arch_stack_walk+0x73/0xf0
>>>>>>     ? usb_hcd_link_urb_to_ep+0x14/0xa0
>>>>>>     ? prepare_transfer+0xff/0x140
>>>>>>     usb_start_wait_urb+0x60/0x160
>>>>>>     usb_control_msg+0xda/0x140
>>>>>>     hub_ext_port_status+0x82/0x100
>>>>>>     hub_event+0x1b1/0x1830
>>>>>>     ? hub_activate+0x58c/0x860
>>>>>>     process_one_work+0x1d4/0x370
>>>>>>     worker_thread+0x48/0x3d0
>>>>>>     ? rescuer_thread+0x360/0x360
>>>>>>     kthread+0x122/0x140
>>>>>>     ? set_kthread_struct+0x40/0x40
>>>>>>     ret_from_fork+0x22/0x30
>>>>>> ---[ end trace da6ffcd9fad23a74 ]---
>>>>>> DMA-API: Mapped at:
>>>>>>     debug_dma_map_page+0x60/0xf0
>>>>>>     dma_map_page_attrs+0xfb/0x250
>>>>>>     usb_hcd_map_urb_for_dma+0x3b1/0x4e0
>>>>>>     usb_hcd_submit_urb+0x93/0xbb0
>>>>>>     usb_start_wait_urb+0x60/0x160
>>>>>> usb 1-1.1: new high-speed USB device number 3 using xhci-hcd
>>>>>> usb 1-1.1: New USB device found, idVendor=0424,
>>>>>> idProduct=ec00,
>>>>>> bcdDevice= 2.00
>>>>>> usb 1-1.1: New USB device strings: Mfr=1, Product=2,
>>>>>> SerialNumber=3
>>>>>> usb 1-1.1: Product: LAN9514
>>>>>> usb 1-1.1: Manufacturer: SMSC
>>>>>> usb 1-1.1: SerialNumber: 00951d0d
>>>>>>
>>>>>>
>>>>> I'm not seeing that at all, but I've also been developing and
>>>>> testing
>>>>> on an ARM based device that has the LAN9500A I'm using built
>>>>> into it.
>>>>>
>>>>> I have also recently got a LAN9500A devkit which I've tried on
>>>>> my
>>>>> Ryzen
>>>>> laptop and that's not throwing that error either.
>>>>>
>>>>> Martyn
>>>> Yes I am using the LAN9514 Evaluation board (EVB9514). Plugging
>>>> the
>>>> board into my desktop with 5.15 Ubuntu PPA kernel I also don't
>>>> see this
>>>> crash.
>>>> OTOH I'm building vanilla kernel so no idea why this happens. It
>>>> might
>>>> be that I have CONFIG_DMA_API_DEBUG and Ubuntu not.
>>>>    
>>>
>>> I suspect this is probably unrelated (directly) to the driver then.
>>
>> Maybe not related to this driver but possibly an old bug in hub.c
>> which
>> only surfaces now due to patch "[PATCH] dma debug: report -EEXIST
>> errors
>> in add_dma_entry"? And only shows when CONFIG_DMA_API_DEBUG is set?
>>
>> Ferry
>>
>>> Martyn
>>>
>>>>
>>
> 


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2021-12-01 22:24 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-22 18:44 [PATCH] net: usb: Correct PHY handling of smsc95xx Martyn Welch
2021-11-23 12:40 ` patchwork-bot+netdevbpf
2021-11-27 17:48 ` Ferry Toth
2021-11-29 12:08   ` Martyn Welch
     [not found]     ` <6a06e3b7-df08-6ec0-6e74-95c21fa43f38@gmail.com>
2021-11-30 18:52       ` Martyn Welch
2021-11-30 21:47         ` Ferry Toth
2021-12-01 10:56           ` Martyn Welch
2021-12-01 22:24             ` Ferry Toth

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