[PATCH 48/84] ALSA: usb-audio - Fix invalid volume resolution on Logitech HD webcam c270

[Kamal Mostafa]

3.8.13.3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <tiwai at suse.de>

commit 11e7064f35bb87da8f427d1aa4bbd8b7473a3993 upstream.

USB audio driver spews an error message when probing Logitech HD
webcam c270:
  ALSA mixer.c:1300 usb_audio: Warning! Unlikely big volume range (=6144), cval->res is probably wrong.
  ALSA mixer.c:1304 usb_audio: [5] FU [Mic Capture Volume] ch = 1, val = 1536/7680/1

Obviously the device needs a fixed volume resolution (cval->res = 384)
like other Logitech devices.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=821735

Reported-and-tested-by: Cristian Rodríguez <crrodriguez at opensuse.org>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/usb/mixer.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 64a564d..0a1e869 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -885,6 +885,7 @@ static void volume_control_quirks(struct usb_mixer_elem_info *cval,
 	case USB_ID(0x046d, 0x0808):
 	case USB_ID(0x046d, 0x0809):
 	case USB_ID(0x046d, 0x081d): /* HD Webcam c510 */
+	case USB_ID(0x046d, 0x0825): /* HD Webcam c270 */
 	case USB_ID(0x046d, 0x0991):
 	/* Most audio usb devices lie about volume resolution.
 	 * Most Logitech webcams have res = 384.
-- 
1.8.1.2