ALSA: usb-audio: Fix autopm error during probing
authorTakashi Iwai <tiwai@suse.de>
Thu, 25 Apr 2013 05:38:15 +0000 (07:38 +0200)
committerTakashi Iwai <tiwai@suse.de>
Thu, 25 Apr 2013 05:46:51 +0000 (07:46 +0200)
commit60af3d037eb8c670dcce31401501d1271e7c5d95
treed3399aae19493e16cec50d613c1f0d72732e4028
parentebfc594c02148b6a85c2f178cf167a44a3c3ce10
ALSA: usb-audio: Fix autopm error during probing

We've got strange errors in get_ctl_value() in mixer.c during
probing, e.g. on Hercules RMX2 DJ Controller:

  ALSA mixer.c:352 cannot get ctl value: req = 0x83, wValue = 0x201, wIndex = 0xa00, type = 4
  ALSA mixer.c:352 cannot get ctl value: req = 0x83, wValue = 0x200, wIndex = 0xa00, type = 4
  ....

It turned out that the culprit is autopm: snd_usb_autoresume() returns
-ENODEV when called during card->probing = 1.

Since the call itself during card->probing = 1 is valid, let's fix the
return value of snd_usb_autoresume() as success.

Reported-and-tested-by: Daniel Schürmann <daschuer@mixxx.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
sound/usb/card.c