ALSA: snd-usb: fix cross-interface streaming devices

[platform/adaptation/renesas_rcar/renesas_kernel.git] / sound / usb / pcm.c

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index e80b668..fd5e982 100644 (file)
--- 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;