This is a note to let you know that I've just added the patch titled ALSA: usb-audio: Fix parsing descriptor of UAC2 processing unit to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: alsa-usb-audio-fix-parsing-descriptor-of-uac2-processing-unit.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a6618f4aedb2b60932d766bd82ae7ce866e842aa Mon Sep 17 00:00:00 2001 From: Kirill Marinushkin <k.marinushkin@xxxxxxxxx> Date: Mon, 19 Mar 2018 07:11:08 +0100 Subject: ALSA: usb-audio: Fix parsing descriptor of UAC2 processing unit 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, Patches currently in stable-queue which might be from k.marinushkin@xxxxxxxxx are queue-4.9/alsa-usb-audio-fix-parsing-descriptor-of-uac2-processing-unit.patch