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

kmarinushkin · tiwai · commit a6618f4aedb2 · 2018-03-19T16:43:41.000+01:00
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: 23caaf1 ("ALSA: usb-mixer: Add support for Audio Class v2.0") Signed-off-by: Kirill Marinushkin <k.marinushkin@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/uapi/linux/usb/audio.h b/include/uapi/linux/usb/audio.h
@@ -370,15 +370,15 @@ 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,
 						   int protocol)
 {
 	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,

Original file line number	Diff line number	Diff line change
`@@ -370,15 +370,15 @@ static inline __u8 uac_processing_unit_bControlSize(struct uac_processing_unit_d`
`370`	`370`	`{`
`371`	`371`	`return (protocol == UAC_VERSION_1) ?`
`372`	`372`	`desc->baSourceID[desc->bNrInPins + 4] :`
`373`		`- desc->baSourceID[desc->bNrInPins + 6];`
	`373`	`+ 2; /* in UAC2, this value is constant */`
`374`	`374`	`}`
`375`	`375`
`376`	`376`	`static inline __u8 uac_processing_unit_bmControls(struct uac_processing_unit_descriptor desc,`
`377`	`377`	`int protocol)`
`378`	`378`	`{`
`379`	`379`	`return (protocol == UAC_VERSION_1) ?`
`380`	`380`	`&desc->baSourceID[desc->bNrInPins + 5] :`
`381`		`- &desc->baSourceID[desc->bNrInPins + 7];`
	`381`	`+ &desc->baSourceID[desc->bNrInPins + 6];`
`382`	`382`	`}`
`383`	`383`
`384`	`384`	`static inline __u8 uac_processing_unit_iProcessing(struct uac_processing_unit_descriptor *desc,`