diff options
| author | Eldad Zack <eldad@fogrefinery.com> | 2012-11-28 23:55:36 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-09-10 01:57:08 +0100 |
| commit | 2ca3bc2ba143bdaf753b88310455074a3d2ed7e4 (patch) | |
| tree | fe254053f92f9f656dfb71380e81efbc98b63a5b /sound/usb | |
| parent | 54811a1992e2c5e318ae91b99ea94c9724bc8f66 (diff) | |
| download | lwn-2ca3bc2ba143bdaf753b88310455074a3d2ed7e4.tar.gz lwn-2ca3bc2ba143bdaf753b88310455074a3d2ed7e4.zip | |
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>
Diffstat (limited to 'sound/usb')
| -rw-r--r-- | sound/usb/mixer.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index aeb26eb08ffa..ae878f9f979d 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -720,8 +720,19 @@ static int check_input_term(struct mixer_build *state, int id, struct usb_audio_ return 0; } case UAC1_PROCESSING_UNIT: - case UAC1_EXTENSION_UNIT: { + case UAC1_EXTENSION_UNIT: + /* UAC2_PROCESSING_UNIT_V2 */ + /* UAC2_EFFECT_UNIT */ { struct uac_processing_unit_descriptor *d = p1; + + if (state->mixer->protocol == UAC_VERSION_2 && + hdr[2] == UAC2_EFFECT_UNIT) { + /* UAC2/UAC1 unit IDs overlap here in an + * uncompatible way. Ignore this unit for now. + */ + return 0; + } + if (d->bNrInPins) { id = d->baSourceID[0]; break; /* continue to parse */ |