diff options
| author | Dan Carpenter <error27@gmail.com> | 2010-04-28 12:29:14 +0400 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2010-05-05 11:57:08 +0400 |
| commit | bfe70783ca8e61f1fc3588cd59c4f1b755e9d3cf (patch) | |
| tree | 45818522458f570d98f90abcbc9cc685a206b48f /sound/core/timer.c | |
| parent | 867f1845c53f52e6b9822bea387c7b16740ba2f8 (diff) | |
| download | linux-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.c | 5 |
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); } |