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authorAndrej Krutak <dev@andree.sk>2016-08-18 23:52:11 +0200
committerTakashi Iwai <tiwai@suse.de>2016-08-22 11:37:16 +0200
commitadc8a43a6d6688272ebffa81789fa857e603dec6 (patch)
tree237a2485013ae0fec8f71c8045241eebf5b161be /sound
parent7e4379eae0e31994ea645db1d13006ea8e5ce539 (diff)
downloadlinux-stericsson-adc8a43a6d6688272ebffa81789fa857e603dec6.tar.gz
ALSA: line6: Give up on the lock while URBs are released.
Done, because line6_stream_stop() locks and calls line6_unlink_audio_urbs(), which in turn invokes audio_out_callback(), which tries to lock 2nd time. Fixes: ============================================= [ INFO: possible recursive locking detected ] 4.4.15+ #15 Not tainted --------------------------------------------- mplayer/3591 is trying to acquire lock: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa27655>] audio_out_callback+0x70/0x110 [snd_usb_line6] but task is already holding lock: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&line6pcm->out.lock)->rlock); lock(&(&line6pcm->out.lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by mplayer/3591: #0: (snd_pcm_link_rwlock){.-.-..}, at: [<bf8d49a7>] snd_pcm_stream_lock+0x1e/0x40 [snd_pcm] #1: (&(&substream->self_group.lock)->rlock){-.-...}, at: [<bf8d49af>] snd_pcm_stream_lock+0x26/0x40 [snd_pcm] #2: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6] stack backtrace: CPU: 0 PID: 3591 Comm: mplayer Not tainted 4.4.15+ #15 Hardware name: Generic AM33XX (Flattened Device Tree) [<c0015d85>] (unwind_backtrace) from [<c001253d>] (show_stack+0x11/0x14) [<c001253d>] (show_stack) from [<c02f1bdf>] (dump_stack+0x8b/0xac) [<c02f1bdf>] (dump_stack) from [<c0076f43>] (__lock_acquire+0xc8b/0x1780) [<c0076f43>] (__lock_acquire) from [<c007810d>] (lock_acquire+0x99/0x1c0) [<c007810d>] (lock_acquire) from [<c06171e7>] (_raw_spin_lock_irqsave+0x3f/0x4c) [<c06171e7>] (_raw_spin_lock_irqsave) from [<bfa27655>] (audio_out_callback+0x70/0x110 [snd_usb_line6]) [<bfa27655>] (audio_out_callback [snd_usb_line6]) from [<c04294db>] (__usb_hcd_giveback_urb+0x53/0xd0) [<c04294db>] (__usb_hcd_giveback_urb) from [<c046388d>] (musb_giveback+0x3d/0x98) [<c046388d>] (musb_giveback) from [<c04647f5>] (musb_urb_dequeue+0x6d/0x114) [<c04647f5>] (musb_urb_dequeue) from [<c042ac11>] (usb_hcd_unlink_urb+0x39/0x98) [<c042ac11>] (usb_hcd_unlink_urb) from [<bfa26a87>] (line6_unlink_audio_urbs+0x6a/0x6c [snd_usb_line6]) [<bfa26a87>] (line6_unlink_audio_urbs [snd_usb_line6]) from [<bfa26acb>] (line6_stream_stop+0x42/0x5c [snd_usb_line6]) [<bfa26acb>] (line6_stream_stop [snd_usb_line6]) from [<bfa26fe7>] (snd_line6_trigger+0xb6/0xf4 [snd_usb_line6]) [<bfa26fe7>] (snd_line6_trigger [snd_usb_line6]) from [<bf8d47b7>] (snd_pcm_do_stop+0x36/0x38 [snd_pcm]) [<bf8d47b7>] (snd_pcm_do_stop [snd_pcm]) from [<bf8d462f>] (snd_pcm_action_single+0x22/0x40 [snd_pcm]) [<bf8d462f>] (snd_pcm_action_single [snd_pcm]) from [<bf8d46f9>] (snd_pcm_action+0xac/0xb0 [snd_pcm]) [<bf8d46f9>] (snd_pcm_action [snd_pcm]) from [<bf8d4b61>] (snd_pcm_drop+0x38/0x64 [snd_pcm]) [<bf8d4b61>] (snd_pcm_drop [snd_pcm]) from [<bf8d6233>] (snd_pcm_common_ioctl1+0x7fe/0xbe8 [snd_pcm]) [<bf8d6233>] (snd_pcm_common_ioctl1 [snd_pcm]) from [<bf8d6779>] (snd_pcm_playback_ioctl1+0x15c/0x51c [snd_pcm]) [<bf8d6779>] (snd_pcm_playback_ioctl1 [snd_pcm]) from [<bf8d6b59>] (snd_pcm_playback_ioctl+0x20/0x28 [snd_pcm]) [<bf8d6b59>] (snd_pcm_playback_ioctl [snd_pcm]) from [<c016714b>] (do_vfs_ioctl+0x3af/0x5c8) Fixes: 63e20df1e5b2 ('ALSA: line6: Reorganize PCM stream handling') Cc: <stable@vger.kernel.org> # v4.0+ Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com> Signed-off-by: Andrej Krutak <dev@andree.sk> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/usb/line6/pcm.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/usb/line6/pcm.c b/sound/usb/line6/pcm.c
index 2bc8879757f9..41aa3355e920 100644
--- a/sound/usb/line6/pcm.c
+++ b/sound/usb/line6/pcm.c
@@ -210,7 +210,9 @@ static void line6_stream_stop(struct snd_line6_pcm *line6pcm, int direction,
spin_lock_irqsave(&pstr->lock, flags);
clear_bit(type, &pstr->running);
if (!pstr->running) {
+ spin_unlock_irqrestore(&pstr->lock, flags);
line6_unlink_audio_urbs(line6pcm, pstr);
+ spin_lock_irqsave(&pstr->lock, flags);
if (direction == SNDRV_PCM_STREAM_CAPTURE) {
line6pcm->prev_fbuf = NULL;
line6pcm->prev_fsize = 0;