• Takashi Iwai's avatar
    ALSA: core: Add snd_card_free_on_error() helper · fee2b871
    Takashi Iwai authored
    This is a small helper function to handle the error path more easily
    when an error happens during the probe for the device with the
    device-managed card.  Since devres releases in the reverser order of
    the creations, usually snd_card_free() gets called at the last in the
    probe error path unless it already reached snd_card_register() calls.
    Due to this nature, when a driver expects the resource releases in
    card->private_free, this might be called too lately.
    
    As a workaround, one should call the probe like:
    
     static int __some_probe(...) { // do real probe.... }
    
     static int some_probe(...)
     {
    	return snd_card_free_on_error(dev, __some_probe(dev, ...));
     }
    
    so that the snd_card_free() is called explicitly at the beginning of
    the error path from the probe.
    
    This function will be used in the upcoming fixes to address the
    regressions by devres usages.
    
    Fixes: e8ad415b ("ALSA: core: Add managed card creation")
    Cc: <stable@vger.kernel.org>
    Link: https://lore.kernel.org/r/20220412093141.8008-2-tiwai@suse.deSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    fee2b871
core.h 15.3 KB