tree b9c37c3c341692eba1bbe54402a081be9d45759e
parent 4d7b86c98e445b075c2c4c3757eb6d3d6efbe72e
author Daniel Mack <zonque@gmail.com> 1363723765 +0100
committer Takashi Iwai <tiwai@suse.de> 1363765380 +0100

ALSA: snd-usb: mixer: ignore -EINVAL in snd_usb_mixer_controls()

Creation of individual mixer controls may fail, but that shouldn't cause
the entire mixer creation to fail. Even worse, if the mixer creation
fails, that will error out the entire device probing.

All the functions called by parse_audio_unit() should return -EINVAL if
they find descriptors that are unsupported or believed to be malformed,
so we can safely handle this error code as a non-fatal condition in
snd_usb_mixer_controls().

That fixes a long standing bug which is commonly worked around by
adding quirks which make the driver ignore entire interfaces. Some of
them might now be unnecessary.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Reported-and-tested-by: Rodolfo Thomazelli <pe.soberbo@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>