[PATCH] fix AB-BA deadlock inversion at cs46xx_dsp_remove_scb
There is a code sequence where the locking is substream->self_group.lock -> ins->scbs[index].lock substream->self_group.lock is interrupt safe, and taken from irq context as well (trace is snipped for brevity) so what can happen is cpu 0 cpu 1 user context user context take ins->scbs[index].lock without disabling interrupts get substream->self_group.lock (irqsafe) try to get ins->scbs[index].lock (spins) interrupt happens try to get substream->self_group.lock (spins) which is an obvious AB-BA deadlock fix is to just take the lock with _irqsafe Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Jaroslav Kysela <perex@suse.cz> Acked-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Showing
Please register or sign in to comment