On (21/05/16 11:49), Takashi Iwai wrote: > Subject: [PATCH] ALSA: intel8x0: Don't update period unless prepared > > The interrupt handler of intel8x0 calls snd_intel8x0_update() whenever > the hardware sets the corresponding status bit for each stream. This > works fine for most cases as long as the hardware behaves properly. > But when the hardware gives a wrong bit set, this leads to a NULL > dereference Oops, and reportedly, this seems what happened on a VM. VM, yes. I didn't see NULL derefs, my VMs crash because of div by zero in `% size`. > For fixing the crash, this patch adds a internal flag indicating that > the stream is ready to be updated, and check it (as well as the flag > being in suspended) to ignore such spurious update. I reproduced the "spurious IRQ" case, and the patch handled it correctly (VM did not crash). > Cc: <stable@xxxxxxxxxxxxxxx> > Reported-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> I'll keep running test, but seems that it works as intended Tested-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
