[alsa-devel] Should snd_card_free() check for null pointer?

Hi,

Before commit f24640648186b (ALSA: Use standard device refcount for card accounting), snd_card_free() would return -EINVAL on a null pointer. Now it ends up in a null pointer dereference. There is at least one driver that can call snd_card_free() with null argument: saa7134_alsa. It can easily be triggered by just inserting and removing the module (no need to have the hardware). I don't think that is a rule, but it seems that the standard behavior of *_free() functions is to check for null pointer. What do you think?

Thanks, Jerome