From bfe70783ca8e61f1fc3588cd59c4f1b755e9d3cf Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 28 Apr 2010 10:29:14 +0200 Subject: 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: [] snd_timer_user_tinterrupt+0x28/0x132 [snd_timer] > {HARDIRQ-ON-W} state was registered at: > [] __lock_acquire+0x654/0x1482 > [] lock_acquire+0x5c/0x73 > [] _raw_spin_lock+0x25/0x34 > [] snd_timer_user_ccallback+0x55/0x95 [snd_timer] > [] snd_timer_notify1+0x53/0xca [snd_timer] Reported-by: Stefan Richter Signed-off-by: Dan Carpenter Signed-off-by: Takashi Iwai --- sound/core/timer.c | 5 +++-- 1 file 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); } -- cgit v1.2.3