ALSA: usb-audio: Use Class Specific EP for UAC3 devices.

bmAtributes offset doesn't exist in the UAC3 CS_EP descriptor.
Hence, checking for pitch control as if it was UAC2 doesn't make
any sense. Use the defined UAC3 offsets instead.

Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support")
Signed-off-by: Jorge Sanjuan <[e-mail]>
Reviewed-by: Ruslan Bilovol <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>

sound/usb/stream.c

···
 
 	if (protocol == UAC_VERSION_1) {
 		attributes = csep->bmAttributes;
-	} else {
+	} else if (protocol == UAC_VERSION_2) {
 		struct uac2_iso_endpoint_descriptor *csep2 =
 			(struct uac2_iso_endpoint_descriptor *) csep;
 
···
 
 		/* emulate the endpoint attributes of a v1 device */
 		if (csep2->bmControls & UAC2_CONTROL_PITCH)
+			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
+	} else { /* UAC_VERSION_3 */
+		struct uac3_iso_endpoint_descriptor *csep3 =
+			(struct uac3_iso_endpoint_descriptor *) csep;
+
+		/* emulate the endpoint attributes of a v1 device */
+		if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
 	}