[ 3.8.y.z extended stable ] Patch "ALSA: ua101: Fix unlocked snd_pcm_stop() call" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ALSA: ua101: Fix unlocked snd_pcm_stop() call

to the linux-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.6.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 3d7ec49fd54dbe3412fc722dbb931e88339cc5db Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai at suse.de>
Date: Thu, 11 Jul 2013 17:58:25 +0200
Subject: ALSA: ua101: Fix unlocked snd_pcm_stop() call

commit 9538aa46c2427d6782aa10036c4da4c541605e0e upstream.

snd_pcm_stop() must be called in the PCM substream lock context.

Acked-by: Clemens Ladisch <clemens at ladisch.de>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/usb/misc/ua101.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/sound/usb/misc/ua101.c b/sound/usb/misc/ua101.c
index 6ad617b..76d8329 100644
--- a/sound/usb/misc/ua101.c
+++ b/sound/usb/misc/ua101.c
@@ -613,14 +613,24 @@ static int start_usb_playback(struct ua101 *ua)

 static void abort_alsa_capture(struct ua101 *ua)
 {
-	if (test_bit(ALSA_CAPTURE_RUNNING, &ua->states))
+	unsigned long flags;
+
+	if (test_bit(ALSA_CAPTURE_RUNNING, &ua->states)) {
+		snd_pcm_stream_lock_irqsave(ua->capture.substream, flags);
 		snd_pcm_stop(ua->capture.substream, SNDRV_PCM_STATE_XRUN);
+		snd_pcm_stream_unlock_irqrestore(ua->capture.substream, flags);
+	}
 }

 static void abort_alsa_playback(struct ua101 *ua)
 {
-	if (test_bit(ALSA_PLAYBACK_RUNNING, &ua->states))
+	unsigned long flags;
+
+	if (test_bit(ALSA_PLAYBACK_RUNNING, &ua->states)) {
+		snd_pcm_stream_lock_irqsave(ua->playback.substream, flags);
 		snd_pcm_stop(ua->playback.substream, SNDRV_PCM_STATE_XRUN);
+		snd_pcm_stream_unlock_irqrestore(ua->playback.substream, flags);
+	}
 }

 static int set_stream_hw(struct ua101 *ua, struct snd_pcm_substream *substream,
--
1.8.1.2