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* [PATCH v2] mdio: aspeed: Fix "Link is Down" issue
@ 2021-11-25  2:44 Dylan Hung
  2021-11-25 14:47 ` Andrew Lunn
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Dylan Hung @ 2021-11-25  2:44 UTC (permalink / raw)
  To: linux-kernel, linux-aspeed, linux-arm-kernel, netdev, andrew,
	joel, kuba, davem, linux, hkallweit1, andrew
  Cc: BMC-SW, stable

The issue happened randomly in runtime.  The message "Link is Down" is
popped but soon it recovered to "Link is Up".

The "Link is Down" results from the incorrect read data for reading the
PHY register via MDIO bus.  The correct sequence for reading the data
shall be:
1. fire the command
2. wait for command done (this step was missing)
3. wait for data idle
4. read data from data register

Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed")
Cc: stable@vger.kernel.org
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>
---
v2: revise commit message

 drivers/net/mdio/mdio-aspeed.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c
index cad820568f75..966c3b4ad59d 100644
--- a/drivers/net/mdio/mdio-aspeed.c
+++ b/drivers/net/mdio/mdio-aspeed.c
@@ -61,6 +61,13 @@ static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
 
 	iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
 
+	rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl,
+				!(ctrl & ASPEED_MDIO_CTRL_FIRE),
+				ASPEED_MDIO_INTERVAL_US,
+				ASPEED_MDIO_TIMEOUT_US);
+	if (rc < 0)
+		return rc;
+
 	rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data,
 				data & ASPEED_MDIO_DATA_IDLE,
 				ASPEED_MDIO_INTERVAL_US,
-- 
2.25.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] mdio: aspeed: Fix "Link is Down" issue
  2021-11-25  2:44 [PATCH v2] mdio: aspeed: Fix "Link is Down" issue Dylan Hung
@ 2021-11-25 14:47 ` Andrew Lunn
  2021-11-25 15:35 ` Russell King (Oracle)
  2021-11-25 16:00 ` patchwork-bot+netdevbpf
  2 siblings, 0 replies; 4+ messages in thread
From: Andrew Lunn @ 2021-11-25 14:47 UTC (permalink / raw)
  To: Dylan Hung
  Cc: linux-kernel, linux-aspeed, linux-arm-kernel, netdev, andrew,
	joel, kuba, davem, linux, hkallweit1, BMC-SW, stable

On Thu, Nov 25, 2021 at 10:44:32AM +0800, Dylan Hung wrote:
> The issue happened randomly in runtime.  The message "Link is Down" is
> popped but soon it recovered to "Link is Up".
> 
> The "Link is Down" results from the incorrect read data for reading the
> PHY register via MDIO bus.  The correct sequence for reading the data
> shall be:
> 1. fire the command
> 2. wait for command done (this step was missing)
> 3. wait for data idle
> 4. read data from data register
> 
> Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed")
> Cc: stable@vger.kernel.org
> Reviewed-by: Joel Stanley <joel@jms.id.au>
> Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] mdio: aspeed: Fix "Link is Down" issue
  2021-11-25  2:44 [PATCH v2] mdio: aspeed: Fix "Link is Down" issue Dylan Hung
  2021-11-25 14:47 ` Andrew Lunn
@ 2021-11-25 15:35 ` Russell King (Oracle)
  2021-11-25 16:00 ` patchwork-bot+netdevbpf
  2 siblings, 0 replies; 4+ messages in thread
From: Russell King (Oracle) @ 2021-11-25 15:35 UTC (permalink / raw)
  To: Dylan Hung
  Cc: linux-kernel, linux-aspeed, linux-arm-kernel, netdev, andrew,
	joel, kuba, davem, hkallweit1, andrew, BMC-SW, stable

On Thu, Nov 25, 2021 at 10:44:32AM +0800, Dylan Hung wrote:
> The issue happened randomly in runtime.  The message "Link is Down" is
> popped but soon it recovered to "Link is Up".
> 
> The "Link is Down" results from the incorrect read data for reading the
> PHY register via MDIO bus.  The correct sequence for reading the data
> shall be:
> 1. fire the command
> 2. wait for command done (this step was missing)
> 3. wait for data idle
> 4. read data from data register
> 
> Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed")
> Cc: stable@vger.kernel.org
> Reviewed-by: Joel Stanley <joel@jms.id.au>
> Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] mdio: aspeed: Fix "Link is Down" issue
  2021-11-25  2:44 [PATCH v2] mdio: aspeed: Fix "Link is Down" issue Dylan Hung
  2021-11-25 14:47 ` Andrew Lunn
  2021-11-25 15:35 ` Russell King (Oracle)
@ 2021-11-25 16:00 ` patchwork-bot+netdevbpf
  2 siblings, 0 replies; 4+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-11-25 16:00 UTC (permalink / raw)
  To: Dylan Hung
  Cc: linux-kernel, linux-aspeed, linux-arm-kernel, netdev, andrew,
	joel, kuba, davem, linux, hkallweit1, andrew, BMC-SW, stable

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 25 Nov 2021 10:44:32 +0800 you wrote:
> The issue happened randomly in runtime.  The message "Link is Down" is
> popped but soon it recovered to "Link is Up".
> 
> The "Link is Down" results from the incorrect read data for reading the
> PHY register via MDIO bus.  The correct sequence for reading the data
> shall be:
> 1. fire the command
> 2. wait for command done (this step was missing)
> 3. wait for data idle
> 4. read data from data register
> 
> [...]

Here is the summary with links:
  - [v2] mdio: aspeed: Fix "Link is Down" issue
    https://git.kernel.org/netdev/net/c/9dbe33cf371b

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] 4+ messages in thread

end of thread, other threads:[~2021-11-25 16:02 UTC | newest]

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2021-11-25  2:44 [PATCH v2] mdio: aspeed: Fix "Link is Down" issue Dylan Hung
2021-11-25 14:47 ` Andrew Lunn
2021-11-25 15:35 ` Russell King (Oracle)
2021-11-25 16:00 ` patchwork-bot+netdevbpf

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