[PATCH] ALSA: usb-audio: Fix parsing descriptor of UAC2 processing unit

[Kirill Marinushkin]

Currently, the offsets in the UAC2 processing unit descriptor are
calculated incorrectly. It causes an issue when connecting the device which
provides such a feature:

~~~~
[84126.724420] usb 1-1.3.1: invalid Processing Unit descriptor (id 18)
~~~~

After this patch is applied, the UAC2 processing unit inits w/o this error.

Fixes: 5e1ddb481776 ("UAPI: (Scripted) Disintegrate include/linux/usb")
Signed-off-by: Kirill Marinushkin <k.marinush...@gmail.com>
Cc: Mark Brown <broo...@kernel.org>
Cc: Jaroslav Kysela <pe...@perex.cz>
Cc: Takashi Iwai <ti...@suse.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Felipe Balbi <felipe.ba...@linux.intel.com>
Cc: Philippe Ombredanne <pombreda...@nexb.com>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: Ruslan Bilovol <ruslan.bilo...@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: alsa-de...@alsa-project.org
---
 include/uapi/linux/usb/audio.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/usb/audio.h b/include/uapi/linux/usb/audio.h
index 17a022c5b414..da3315ed1bcd 100644
--- a/include/uapi/linux/usb/audio.h
+++ b/include/uapi/linux/usb/audio.h
@@ -370,7 +370,7 @@ static inline __u8 uac_processing_unit_bControlSize(struct 
uac_processing_unit_d
 {
        return (protocol == UAC_VERSION_1) ?
                desc->baSourceID[desc->bNrInPins + 4] :
-               desc->baSourceID[desc->bNrInPins + 6];
+               2; /* in UAC2, this value is constant */
 }
 
 static inline __u8 *uac_processing_unit_bmControls(struct 
uac_processing_unit_descriptor *desc,
@@ -378,7 +378,7 @@ static inline __u8 *uac_processing_unit_bmControls(struct 
uac_processing_unit_de
 {
        return (protocol == UAC_VERSION_1) ?
                &desc->baSourceID[desc->bNrInPins + 5] :
-               &desc->baSourceID[desc->bNrInPins + 7];
+               &desc->baSourceID[desc->bNrInPins + 6];
 }
 
 static inline __u8 uac_processing_unit_iProcessing(struct 
uac_processing_unit_descriptor *desc,
-- 
2.13.6