ALSA: usb-audio: skip UAC2 EFFECT_UNIT
authorEldad Zack <eldad@fogrefinery.com>
Wed, 28 Nov 2012 22:55:36 +0000 (23:55 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 14 Apr 2014 13:44:30 +0000 (06:44 -0700)
commitd47b372591bb5e87f6534b3d66cf7d029eed237f
tree879e461f5b1b57ca95e7244e3cc5c32a34db9347
parentff15138a16c56ff43adeea27f90d46f59b69dcfd
ALSA: usb-audio: skip UAC2 EFFECT_UNIT

commit 5dae5fd24071319bb67d3375217d5b0b6d16cb0b upstream.

Current code mishandles the case where the device is a UAC2
and the bDescriptorSubtype is a UAC2 Effect Unit (0x07).
It tries to parse it as a Processing Unit (which is similar to two
other UAC1 units with overlapping subtypes), but since the structure
is different (See: 4.7.2.10, 4.7.2.11 in UAC2 standard), the parsing
is done incorrectly and prevents the device from initializing.
For now, just ignore the unit.

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sound/usb/mixer.c