The code releasing the each card object may access to NULL when a
bogus count is given. Add a NULL check just to make sure.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
For the plug-and-play hardware, like USB devices, it may be helpful
to manage the sound state periodically, before the devices are removed.
This change implements new commands 'daemon' and 'rdaemon' to save
the sound state in defined intervals when the sound controls are changed.
The udev rules can notify the daemon using the 'kill' or 'nrestore'
commands to rescan available cards in the system.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
