Patchwork [3.5.y.z,extended,stable] Patch "ALSA: usb - fix race in creation of M-Audio Fast track pro" has been added to staging queue

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Submitter Herton Ronaldo Krzesinski
Date Jan. 23, 2013, 9:39 p.m.
Message ID <1358977177-23924-1-git-send-email-herton.krzesinski@canonical.com>
Download mbox | patch
Permalink /patch/215043/
State New
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Comments

Herton Ronaldo Krzesinski - Jan. 23, 2013, 9:39 p.m.
This is a note to let you know that I have just added a patch titled

    ALSA: usb - fix race in creation of M-Audio Fast track pro

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

From 4d5dcd62195ab332b4e073ed2f01885d73890144 Mon Sep 17 00:00:00 2001
From: David Henningsson <david.henningsson@canonical.com>
Date: Fri, 4 Jan 2013 17:02:18 +0100
Subject: [PATCH] ALSA: usb - fix race in creation of M-Audio Fast track pro
 driver

commit b98ae2729dea161edc96c9d177459b6c28bcbba5 upstream.

A patch in the 3.2 kernel caused regression with hotplugging the
M-Audio Fast track pro, or sound after suspend. I don't have the
device so I haven't done a full analysis, but it seems userspace
(both udev and pulseaudio) got confused when a card was created,
immediately destroyed, and then created again.

However, at least one person in the bug report (martin djfun)
reports that this patch resolves the issue for him. It also leaves
a message in the log:
"snd-usb-audio: probe of 1-1.1:1.1 failed with error -5" which is
a bit misleading. It is better than non-working audio, but maybe
there's a more elegant solution?

BugLink: https://bugs.launchpad.net/bugs/1095315
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 sound/usb/quirks.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--
1.7.9.5

Patch

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 2781726..c46171a 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -387,11 +387,13 @@  static int snd_usb_fasttrackpro_boot_quirk(struct usb_device *dev)
 		 * rules
 		 */
 		err = usb_driver_set_configuration(dev, 2);
-		if (err < 0) {
+		if (err < 0)
 			snd_printdd("error usb_driver_set_configuration: %d\n",
 				    err);
-			return -ENODEV;
-		}
+		/* Always return an error, so that we stop creating a device
+		   that will just be destroyed and recreated with a new
+		   configuration */
+		return -ENODEV;
 	} else
 		snd_printk(KERN_INFO "usb-audio: Fast Track Pro config OK\n");