From f58161ba1b05a968e5136824b5a16b714b6a5317 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 8 Nov 2012 08:52:45 +0100 Subject: ALSA: usb-audio: Fix crash at re-preparing the PCM stream There are bug reports of a crash with USB-audio devices when PCM prepare is performed immediately after the stream is stopped via trigger callback. It turned out that the problem is that we don't wait until all URBs are killed. This patch adds a new function to synchronize the pending stop operation on an endpoint, and calls in the prepare callback for avoiding the crash above. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=49181 Reported-and-tested-by: Artem S. Tashkinov Cc: [v3.6] Signed-off-by: Takashi Iwai --- sound/usb/pcm.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'sound/usb/pcm.c') diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 37428f74dbb6..5c12a3fe8c3e 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -568,6 +568,9 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream) goto unlock; } + snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint); + snd_usb_endpoint_sync_pending_stop(subs->data_endpoint); + ret = set_format(subs, subs->cur_audiofmt); if (ret < 0) goto unlock; -- cgit