sound fixes for 5.4-rc6
A copule of regression fixes and a fix for mutex deadlock at
hog-unplug, as well as other device-specific fixes:
- A commit for avoiding the spurious unsolicited interrupt on HD-
audio bus caused a stall at shutdown, so it's reverted now.
- The recent support of AMD/Nvidia audio component binding caused
a mutex deadlock; fixed by splitting to another mutex
- The device hot-unplug and the ALSA timer close combo may lead to
another mutex deadlock; fixed by moving put_device() calls
- Usual device-specific small quirks for HD- and USB-audio drivers
- An old error check fix in FireWire driver
ALSA: timer: Fix mutex deadlock at releasing card
When a card is disconnected while in use, the system waits until all
opened files are closed then releases the card. This is done via
put_device() of the card device in each device release code.
The recently reported mutex deadlock bug happens in this code path;
snd_timer_close() for the timer device deals with the global
register_mutex and it calls put_device() there. When this timer
device is the last one, the card gets freed and it eventually calls
snd_timer_free(), which has again the protection with the global
register_mutex -- boom.
Basically put_device() call itself is race-free, so a relative simple
workaround is to move this put_device() call out of the mutex. For
achieving that, in this patch, snd_timer_close_locked() got a new
argument to store the card device pointer in return, and each caller
invokes put_device() with the returned object after the mutex unlock.
Reported-and-tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
1 file changed
