[PATCH 4.14 147/167] ALSA: usb-audio: add implicit fb quirk for Behringer UFX1204

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

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

From: Lassi Ylikojola <redacted>

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 <redacted>
Cc: <redacted>
Signed-off-by: Takashi Iwai <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 sound/usb/pcm.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c

@@ -357,6 +357,15 @@ 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 &&