ALSA: usb - disable broken hw volume for Tenx TP6911

While going through Ubuntu bugs, I discovered this patch being
posted and a confirmation that the patch works as expected.

Finding out how the hw volume really works would be preferrable
to just disabling the broken one, but this would be better than
nothing.

Credit: sndfnsdfin (qawsnews)
BugLink: https://bugs.launchpad.net/bugs/559939Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/mixer.c

@@ -1267,6 +1267,13 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
 		/* disable non-functional volume control */
 		master_bits &= ~UAC_CONTROL_BIT(UAC_FU_VOLUME);
 		break;
+	case USB_ID(0x1130, 0xf211):
+		snd_printk(KERN_INFO
+			   "usbmixer: volume control quirk for Tenx TP6911 Audio Headset\n");
+		/* disable non-functional volume control */
+		channels = 0;
+		break;
+
 	}
 	if (channels > 0)
 		first_ch_bits = snd_usb_combine_bytes(bmaControls + csize, csize);