[PATCH 3.16 225/410] ALSA: usb-audio: add implicit fb quirk for Behringer UFX1204

[Ben Hutchings]

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

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

From: Lassi Ylikojola <lassi.ylikojola@xxxxxxxxx>

commit 5e35dc0338d85ccebacf3f77eca1e5dea73155e8 upstream.

Add quirk to ensure a sync endpoint is properly configured.
This patch is a fix for same symptoms on Behringer UFX1204 as patch
from Albertto Aquirre on Dec 8 2016 for Axe-Fx II.

Signed-off-by: Lassi Ylikojola <lassi.ylikojola@xxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 sound/usb/pcm.c | 9 +++++++++
 1 file changed, 9 insertions(+)

--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -348,6 +348,15 @@ static int set_sync_ep_implicit_fb_quirk
 
 		alts = &iface->altsetting[1];
 		goto add_sync_ep;
+	case USB_ID(0x1397, 0x0002):
+		ep = 0x81;
+		iface = usb_ifnum_to_if(dev, 1);
+
+		if (!iface || iface->num_altsetting == 0)
+			return -EINVAL;
+
+		alts = &iface->altsetting[1];
+		goto add_sync_ep;
 	}
 	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&