diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index e80b6687f43a..fd5e982fc98c 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -236,6 +236,21 @@ static int start_endpoints(struct snd_usb_substream *subs, int can_sleep) !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) { struct snd_usb_endpoint *ep = subs->sync_endpoint; + if (subs->data_endpoint->iface != subs->sync_endpoint->iface || + subs->data_endpoint->alt_idx != subs->sync_endpoint->alt_idx) { + err = usb_set_interface(subs->dev, + subs->sync_endpoint->iface, + subs->sync_endpoint->alt_idx); + if (err < 0) { + snd_printk(KERN_ERR + "%d:%d:%d: cannot set interface (%d)\n", + subs->dev->devnum, + subs->sync_endpoint->iface, + subs->sync_endpoint->alt_idx, err); + return -EIO; + } + } + snd_printdd(KERN_DEBUG "Starting sync EP @%p\n", ep); ep->sync_slave = subs->data_endpoint;