[PATCH] ALSA: usb-audio: fix feature unit parser for UAC2
Daniel Mack
daniel at caiaq.de
Thu May 27 18:28:25 CEST 2010
Fix a small off-by-one bug which causes the feature unit to announce a
wrong number of channels. This leads to illegal requests sent to the
firmware eventually.
Signed-off-by: Daniel Mack <daniel at caiaq.de>
---
sound/usb/mixer.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 97dd176..03ce971 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1126,7 +1126,7 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
} else {
struct uac2_feature_unit_descriptor *ftr = _ftr;
csize = 4;
- channels = (hdr->bLength - 6) / 4;
+ channels = (hdr->bLength - 6) / 4 - 1;
bmaControls = ftr->bmaControls;
}
--
1.7.1
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