[PATCH 3.16 180/245] ALSA: usb-audio: add implicit fb quirk for Axe-Fx II

[Ben Hutchings]

3.16.83-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Alberto Aguirre <albaguirre@xxxxxxxxx>

commit 17f08b0d9aafccdb10038ab6dbd9ddb6433c13e2 upstream.

The Axe-Fx II implicit feedback end point and the data sync endpoint
are in different interface descriptors. Add quirk to ensure a sync
endpoint is properly configured.

Signed-off-by: Alberto Aguirre <albaguirre@xxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 sound/usb/pcm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -351,6 +351,15 @@ static int set_sync_ep_implicit_fb_quirk
 
 		alts = &iface->altsetting[1];
 		goto add_sync_ep;
+	case USB_ID(0x2466, 0x8003):
+		ep = 0x86;
+		iface = usb_ifnum_to_if(dev, 2);
+
+		if (!iface || iface->num_altsetting == 0)
+			return -EINVAL;
+
+		alts = &iface->altsetting[1];
+		goto add_sync_ep;
 	case USB_ID(0x1397, 0x0002):
 		ep = 0x81;
 		iface = usb_ifnum_to_if(dev, 1);
@@ -360,6 +369,7 @@ static int set_sync_ep_implicit_fb_quirk
 
 		alts = &iface->altsetting[1];
 		goto add_sync_ep;
+
 	}
 	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&