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authorDan Carpenter <error27@gmail.com>2010-04-28 12:29:14 +0400
committerTakashi Iwai <tiwai@suse.de>2010-05-05 11:57:08 +0400
commitbfe70783ca8e61f1fc3588cd59c4f1b755e9d3cf (patch)
tree45818522458f570d98f90abcbc9cc685a206b48f /sound/core/timer.c
parent867f1845c53f52e6b9822bea387c7b16740ba2f8 (diff)
downloadlinux-bfe70783ca8e61f1fc3588cd59c4f1b755e9d3cf.tar.xz
ALSA: take tu->qlock with irqs disabled
We should disable irqs when we take the tu->qlock because it is used in the irq handler. The only place that doesn't is snd_timer_user_ccallback(). Most of the time snd_timer_user_ccallback() is called with interrupts disabled but the the first ti->ccallback() call in snd_timer_notify1() has interrupts enabled. This was caught by lockdep which generates the following message: > ================================= > [ INFO: inconsistent lock state ] > 2.6.34-rc5 #5 > --------------------------------- > inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. > dolphin/4003 [HC1[1]:SC0[0]:HE0:SE1] takes: > (&(&tu->qlock)->rlock){?.+...}, at: [<f84ec472>] snd_timer_user_tinterrupt+0x28/0x132 [snd_timer] > {HARDIRQ-ON-W} state was registered at: > [<c1048de9>] __lock_acquire+0x654/0x1482 > [<c1049c73>] lock_acquire+0x5c/0x73 > [<c125ac3e>] _raw_spin_lock+0x25/0x34 > [<f84ec370>] snd_timer_user_ccallback+0x55/0x95 [snd_timer] > [<f84ecc4b>] snd_timer_notify1+0x53/0xca [snd_timer] Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/timer.c')
-rw-r--r--sound/core/timer.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/sound/core/timer.c b/sound/core/timer.c
index 73943651caed..5040c7b862fe 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1160,6 +1160,7 @@ static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
{
struct snd_timer_user *tu = timeri->callback_data;
struct snd_timer_tread r1;
+ unsigned long flags;
if (event >= SNDRV_TIMER_EVENT_START &&
event <= SNDRV_TIMER_EVENT_PAUSE)
@@ -1169,9 +1170,9 @@ static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
r1.event = event;
r1.tstamp = *tstamp;
r1.val = resolution;
- spin_lock(&tu->qlock);
+ spin_lock_irqsave(&tu->qlock, flags);
snd_timer_user_append_to_tqueue(tu, &r1);
- spin_unlock(&tu->qlock);
+ spin_unlock_irqrestore(&tu->qlock, flags);
kill_fasync(&tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}