ALSA: take tu->qlock with irqs disabled
commitbfe70783ca8e61f1fc3588cd59c4f1b755e9d3cf
authorDan Carpenter <error27@gmail.com>
Wed, 28 Apr 2010 08:29:14 +0000 (28 10:29 +0200)
committerTakashi Iwai <tiwai@suse.de>
Wed, 5 May 2010 07:57:08 +0000 (5 09:57 +0200)
tree45818522458f570d98f90abcbc9cc685a206b48f
parent867f1845c53f52e6b9822bea387c7b16740ba2f8
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>
sound/core/timer.c