From 87087b85a7e45d31a31ec2e71fb3dc872a67eb52 Mon Sep 17 00:00:00 2001
From: Hans Petter Selasky <hselasky@FreeBSD.org>
Date: Tue, 24 Mar 2015 09:21:53 +0000
Subject: [PATCH] Use the feedback value from the synchronization endpoint as
 fallback when there is no recording channel.

MFC after:	3 days
PR: 		198444
---
 sys/dev/sound/usb/uaudio.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sys/dev/sound/usb/uaudio.c b/sys/dev/sound/usb/uaudio.c
index d99002e30cb..8822bf0403c 100644
--- a/sys/dev/sound/usb/uaudio.c
+++ b/sys/dev/sound/usb/uaudio.c
@@ -2026,6 +2026,13 @@ uaudio_chan_play_sync_callback(struct usb_xfer *xfer, usb_error_t error)
 		DPRINTF("Comparing %d Hz :: %d Hz\n",
 		    (int)temp, (int)sample_rate);
 
+		/*
+		 * Use feedback value as fallback when there is no
+		 * recording channel:
+		 */
+		if (ch->priv_sc->sc_rec_chan.num_alt == 0)
+			ch->jitter_curr = temp - sample_rate;
+
 		ch->feedback_rate = temp;
 		break;