This is a note to let you know that I've just added the patch titled
ALSA: aloop - Fix possible IRQ lock inversion
to the 2.6.38-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-aloop-fix-possible-irq-lock-inversion.patch
and it can be found in the queue-2.6.38 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 98d21df431ad55281e1abf780f8d51e3391900b2 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <[email protected]>
Date: Fri, 18 Mar 2011 07:31:53 +0100
Subject: ALSA: aloop - Fix possible IRQ lock inversion
From: Takashi Iwai <[email protected]>
commit 98d21df431ad55281e1abf780f8d51e3391900b2 upstream.
loopback_pos_update() can be called in the timer callback, thus the lock
held should be irq-safe. Otherwise you'll get AB/BA deadlock together
with substream->self_group.lock.
Reported-and-tested-by: Knut Petersen <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
sound/drivers/aloop.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -482,8 +482,9 @@ static unsigned int loopback_pos_update(
cable->streams[SNDRV_PCM_STREAM_CAPTURE];
unsigned long delta_play = 0, delta_capt = 0;
unsigned int running;
+ unsigned long flags;
- spin_lock(&cable->lock);
+ spin_lock_irqsave(&cable->lock, flags);
running = cable->running ^ cable->pause;
if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
delta_play = jiffies - dpcm_play->last_jiffies;
@@ -495,10 +496,8 @@ static unsigned int loopback_pos_update(
dpcm_capt->last_jiffies += delta_capt;
}
- if (delta_play == 0 && delta_capt == 0) {
- spin_unlock(&cable->lock);
- return running;
- }
+ if (delta_play == 0 && delta_capt == 0)
+ goto unlock;
if (delta_play > delta_capt) {
loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
@@ -510,14 +509,14 @@ static unsigned int loopback_pos_update(
delta_capt = delta_play;
}
- if (delta_play == 0 && delta_capt == 0) {
- spin_unlock(&cable->lock);
- return running;
- }
+ if (delta_play == 0 && delta_capt == 0)
+ goto unlock;
+
/* note delta_capt == delta_play at this moment */
loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
- spin_unlock(&cable->lock);
+ unlock:
+ spin_unlock_irqrestore(&cable->lock, flags);
return running;
}
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.38/alsa-ctxfi-clear-input-settings-before-initialization.patch
queue-2.6.38/alsa-ctxfi-fix-spdif-status-retrieval.patch
queue-2.6.38/alsa-hda-fix-volume-control-naming-for-surround-speakers-on-realtek-auto-parser.patch
queue-2.6.38/alsa-hda-enable-surround-and-subwoofer-on-lenovo-ideapad-y530.patch
queue-2.6.38/alsa-sound-pci-asihpi-check-adapter-index-in-hpi_ioctl.patch
queue-2.6.38/alsa-ctxfi-fix-incorrect-spdif-status-bit-mask.patch
queue-2.6.38/alsa-hda-fix-digital-mic-selection-in-mixer-on-92hd8x-codecs.patch
queue-2.6.38/alsa-hda-realtek-alc88x-do-not-over-initialize-speakers-and-hp-that-are-primary-outputs.patch
queue-2.6.38/alsa-aloop-fix-possible-irq-lock-inversion.patch
queue-2.6.38/alsa-hda-fixup-unnecessary-volume-control-index-on-realtek-alc88x.patch
queue-2.6.38/xhci-fix-cycle-bit-calculation-during-stall-handling.patch
queue-2.6.38/alsa-hda-initialize-special-cases-for-input-src-in-init-phase.patch
queue-2.6.38/xhci-update-internal-dequeue-pointers-after-stalls.patch
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