| From | Ben Hutchings <> | Date | Sun, 08 Sep 2013 03:52:01 +0100 | Subject | [018/121] ALSA: usb-audio: skip UAC2 EFFECT_UNIT |
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3.2.51-rc1 review patch. If anyone has any objections, please let me know.
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From: Eldad Zack <eldad@fogrefinery.com>
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> --- sound/usb/mixer.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
--- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -720,8 +720,19 @@ static int check_input_term(struct mixer 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 */
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