4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kirill Marinushkin <k.marinushkin@xxxxxxxxx> commit a6618f4aedb2b60932d766bd82ae7ce866e842aa upstream. 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: 23caaf19b11e ("ALSA: usb-mixer: Add support for Audio Class v2.0") Signed-off-by: Kirill Marinushkin <k.marinushkin@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/uapi/linux/usb/audio.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/include/uapi/linux/usb/audio.h +++ b/include/uapi/linux/usb/audio.h @@ -369,7 +369,7 @@ static inline __u8 uac_processing_unit_b { 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, @@ -377,7 +377,7 @@ static inline __u8 *uac_processing_unit_ { 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,