[PATCH] maple: fix device detection

[PATCH] maple: fix device detection

[Adrian McMenamin]

The maple bus driver that went into the kernel mainline in September 2007 contained some bugs which were revealed by the update of the kobj code for the current release series. Unfortunately those bugs also helped ensure maple devices were properly detected. This patch (against the current git) now ensures that devices are properly detected again.

(A previous attempt to fix this by delaying initialisation only partially fixed this - as became apparent when the bus was fully loaded)

Signed-off-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
---



diff -ruN ./a/drivers/sh/maple/maple.c ./b/drivers/sh/maple/maple.c
--- ./a/drivers/sh/maple/maple.c	2008-02-21 20:42:17.000000000 +0000
+++ ./b/drivers/sh/maple/maple.c	2008-02-24 13:59:09.000000000 +0000
@@ -1,7 +1,7 @@
 /*
  * Core maple bus functionality
  *
- *  Copyright (C) 2007 Adrian McMenamin
+ *  Copyright (C) 2007, 2008 Adrian McMenamin
  *
  * Based on 2.4 code by:
  *
@@ -18,7 +18,6 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/device.h>
-#include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/io.h>
@@ -54,7 +53,7 @@
 static int subdevice_map[MAPLE_PORTS];
 static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
 static unsigned long maple_pnp_time;
-static int started, scanning, liststatus, realscan;
+static int started, scanning, liststatus, fullscan;
 static struct kmem_cache *maple_queue_cache;
 
 struct maple_device_specify {
@@ -62,6 +61,9 @@
 	int unit;
 };
 
+static bool checked[4];
+static struct maple_device *baseunits[4];
+
 /**
  *  maple_driver_register - register a device driver
  *  automatically makes the driver bus a maple bus
@@ -309,11 +311,9 @@
 		else
 			break;
 
-	if (realscan) {
-		printk(KERN_INFO "Maple device detected: %s\n",
-			mdev->product_name);
-		printk(KERN_INFO "Maple device: %s\n", mdev->product_licence);
-	}
+	printk(KERN_INFO "Maple device detected: %s\n",
+		mdev->product_name);
+	printk(KERN_INFO "Maple device: %s\n", mdev->product_licence);
 
 	function = be32_to_cpu(mdev->devinfo.function);
 
@@ -323,10 +323,9 @@
 		mdev->driver = &maple_dummy_driver;
 		sprintf(mdev->dev.bus_id, "%d:0.port", mdev->port);
 	} else {
-		if (realscan)
-			printk(KERN_INFO
-				"Maple bus at (%d, %d): Function 0x%lX\n",
-				mdev->port, mdev->unit, function);
+		printk(KERN_INFO
+			"Maple bus at (%d, %d): Function 0x%lX\n",
+			mdev->port, mdev->unit, function);
 
 		matched =
 		    bus_for_each_drv(&maple_bus_type, NULL, mdev,
@@ -334,9 +333,8 @@
 
 		if (matched == 0) {
 			/* Driver does not exist yet */
-			if (realscan)
-				printk(KERN_INFO
-					"No maple driver found.\n");
+			printk(KERN_INFO
+				"No maple driver found.\n");
 			mdev->driver = &maple_dummy_driver;
 		}
 		sprintf(mdev->dev.bus_id, "%d:0%d.%lX", mdev->port,
@@ -472,9 +470,12 @@
 		maple_detach_driver(mdev);
 		return;
 	}
-	if (!started) {
-		printk(KERN_INFO "No maple devices attached to port %d\n",
-		       mdev->port);
+	if (!started || !fullscan) {
+		if (checked[mdev->port] == false) {
+			checked[mdev->port] = true;
+			printk(KERN_INFO "No maple devices attached"
+				" to port %d\n", mdev->port);
+		}
 		return;
 	}
 	maple_clean_submap(mdev);
@@ -485,8 +486,14 @@
 				   char *recvbuf)
 {
 	char submask;
-	if ((!started) || (scanning == 2)) {
-		maple_attach_driver(mdev);
+	if (!started || (scanning == 2) || !fullscan) {
+		if ((mdev->unit == 0) && (checked[mdev->port] == false)) {
+			checked[mdev->port] = true;
+			maple_attach_driver(mdev);
+		} else {
+			if (mdev->unit != 0)
+				maple_attach_driver(mdev);
+		}
 		return;
 	}
 	if (mdev->unit == 0) {
@@ -505,6 +512,7 @@
 	struct maple_device *dev;
 	char *recvbuf;
 	enum maple_code code;
+	int i;
 
 	if (!maple_dma_done())
 		return;
@@ -557,6 +565,19 @@
 		} else
 			scanning = 0;
 
+		if (!fullscan) {
+			fullscan = 1;
+			for (i = 0; i < MAPLE_PORTS; i++) {
+				if (checked[i] == false) {
+					fullscan = 0;
+					dev = baseunits[i];
+					dev->mq->command =
+						MAPLE_COMMAND_DEVINFO;
+					dev->mq->length = 0;
+					maple_add_packet(dev->mq);
+				}
+			}
+		}
 		if (started == 0)
 			started = 1;
 	}
@@ -694,7 +715,9 @@
 
 	/* setup maple ports */
 	for (i = 0; i < MAPLE_PORTS; i++) {
+		checked[i] = false;
 		mdev[i] = maple_alloc_dev(i, 0);
+		baseunits[i] = mdev[i];
 		if (!mdev[i]) {
 			while (i-- > 0)
 				maple_free_dev(mdev[i]);
@@ -703,12 +726,9 @@
 		mdev[i]->mq->command = MAPLE_COMMAND_DEVINFO;
 		mdev[i]->mq->length = 0;
 		maple_add_packet(mdev[i]->mq);
-		/* delay aids hardware detection */
-		mdelay(5);
 		subdevice_map[i] = 0;
 	}
 
-	realscan = 1;
 	/* setup maplebus hardware */
 	maplebus_dma_reset();
 	/* initial detection */

Re: [PATCH] maple: fix device detection

[Adrian McMenamin]

On Sun, 2008-02-24 at 14:30 +0000, Adrian McMenamin wrote:
> The maple bus driver that went into the kernel mainline in September 2007 contained some bugs which were revealed by the update of the kobj code for the current release series. Unfortunately those bugs also helped ensure maple devices were properly detected. This patch (against the current git) now ensures that devices are properly detected again.
> 

Further testing has shown this has introduced another bug, this time
limiting the effectiveness of subdevice detection. Please ignore this
while I work on a fix.

Re: [PATCH] maple: fix device detection

[Adrian McMenamin]

On Sun, 2008-02-24 at 21:50 +0000, Adrian McMenamin wrote:
> On Sun, 2008-02-24 at 14:30 +0000, Adrian McMenamin wrote:
> > The maple bus driver that went into the kernel mainline in September 2007 contained some bugs which were revealed by the update of the kobj code for the current release series. Unfortunately those bugs also helped ensure maple devices were properly detected. This patch (against the current git) now ensures that devices are properly detected again.
> > 
> 
> Further testing has shown this has introduced another bug, this time
> limiting the effectiveness of subdevice detection. Please ignore this
> while I work on a fix.
> 
Sorry for the confusion, in fact there is nothing wrong with this code
(ie it should be applied), the error was in the driver for the Dreamcast
controller (the device, in general, into which the subdevices are
plugged in and out).

I will post a fix for that.

Sorry again.

Re: [PATCH] maple: fix device detection

[Paul Mundt]

On Sun, Feb 24, 2008 at 10:32:53PM +0000, Adrian McMenamin wrote:
> On Sun, 2008-02-24 at 21:50 +0000, Adrian McMenamin wrote:
> > On Sun, 2008-02-24 at 14:30 +0000, Adrian McMenamin wrote:
> > > The maple bus driver that went into the kernel mainline in
> > > September 2007 contained some bugs which were revealed by the
> > > update of the kobj code for the current release series.
> > > Unfortunately those bugs also helped ensure maple devices were
> > > properly detected. This patch (against the current git) now ensures
> > > that devices are properly detected again.
> > > 
> > 
> > Further testing has shown this has introduced another bug, this time
> > limiting the effectiveness of subdevice detection. Please ignore this
> > while I work on a fix.
> > 
> Sorry for the confusion, in fact there is nothing wrong with this code
> (ie it should be applied), the error was in the driver for the Dreamcast
> controller (the device, in general, into which the subdevices are
> plugged in and out).
> 
> I will post a fix for that.
> 
> Sorry again.
> 
So what exactly is supposed to be applied here?

Re: [PATCH] maple: fix device detection

[Adrian McMenamin]

On Mon, 2008-02-25 at 14:33 +0900, Paul Mundt wrote:
> On Sun, Feb 24, 2008 at 10:32:53PM +0000, Adrian McMenamin wrote:
> > On Sun, 2008-02-24 at 21:50 +0000, Adrian McMenamin wrote:
> > > On Sun, 2008-02-24 at 14:30 +0000, Adrian McMenamin wrote:
> > > > The maple bus driver that went into the kernel mainline in
> > > > September 2007 contained some bugs which were revealed by the
> > > > update of the kobj code for the current release series.
> > > > Unfortunately those bugs also helped ensure maple devices were
> > > > properly detected. This patch (against the current git) now ensures
> > > > that devices are properly detected again.
> > > > 
> > > 
> > > Further testing has shown this has introduced another bug, this time
> > > limiting the effectiveness of subdevice detection. Please ignore this
> > > while I work on a fix.
> > > 
> > Sorry for the confusion, in fact there is nothing wrong with this code
> > (ie it should be applied), the error was in the driver for the Dreamcast
> > controller (the device, in general, into which the subdevices are
> > plugged in and out).
> > 
> > I will post a fix for that.
> > 
> > Sorry again.
> > 
> So what exactly is supposed to be applied here?

The patch at the start of this thread - ie
http://lkml.org/lkml/2008/2/24/125  - this should really go in now as it
fixes a problem with current code.

In addition there are two patch sets to add new device support:

http://lkml.org/lkml/2008/2/24/211    - maple controller

http://lkml.org/lkml/2008/2/24/121  (thread) - maple mouse

Re: [PATCH] maple: fix device detection

[Paul Mundt]

On Mon, Feb 25, 2008 at 07:40:26AM +0000, Adrian McMenamin wrote:
> On Mon, 2008-02-25 at 14:33 +0900, Paul Mundt wrote:
> > On Sun, Feb 24, 2008 at 10:32:53PM +0000, Adrian McMenamin wrote:
> > > On Sun, 2008-02-24 at 21:50 +0000, Adrian McMenamin wrote:
> > > > On Sun, 2008-02-24 at 14:30 +0000, Adrian McMenamin wrote:
> > > > > The maple bus driver that went into the kernel mainline in
> > > > > September 2007 contained some bugs which were revealed by the
> > > > > update of the kobj code for the current release series.
> > > > > Unfortunately those bugs also helped ensure maple devices were
> > > > > properly detected. This patch (against the current git) now ensures
> > > > > that devices are properly detected again.
> > > > > 
> > > > 
> > > > Further testing has shown this has introduced another bug, this time
> > > > limiting the effectiveness of subdevice detection. Please ignore this
> > > > while I work on a fix.
> > > > 
> > > Sorry for the confusion, in fact there is nothing wrong with this code
> > > (ie it should be applied), the error was in the driver for the Dreamcast
> > > controller (the device, in general, into which the subdevices are
> > > plugged in and out).
> > > 
> > > I will post a fix for that.
> > > 
> > > Sorry again.
> > > 
> > So what exactly is supposed to be applied here?
> 
> The patch at the start of this thread - ie
> http://lkml.org/lkml/2008/2/24/125  - this should really go in now as it
> fixes a problem with current code.
> 
Ok, that's applied. Note that the original body was horribly word
wrapped, and your patch was not in -p1 format (while others in the series
are, for reasons that aren't entirely obvious).

> In addition there are two patch sets to add new device support:
> 
> http://lkml.org/lkml/2008/2/24/211    - maple controller
> 
> http://lkml.org/lkml/2008/2/24/121  (thread) - maple mouse
> 
This is not 2.6.25 material. Once you have Acked-by's from the input
folks, I'll queue these up in my 2.6.26 tree. The bus unplug thing is
rather unusual, I don't know if Greg has any comments on that or not.