1 files changed, 12 insertions, 5 deletions

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 498a2d8fa4b..4aa4678e0a0 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -216,6 +216,11 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
         }
 
         switch (protocol) {
+        default:
+                snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n",
+                            protocol);
+                /* fall through */
+
         case UAC_VERSION_1: {
                 struct uac1_ac_header_descriptor *h1 = control_header;
 
@@ -253,10 +258,6 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 
                 break;
         }
-
-        default:
-                snd_printk(KERN_ERR "unknown protocol version 0x%02x\n", protocol);
-                return -EINVAL;
         }
 
         return 0;
@@ -480,7 +481,13 @@ static void *snd_usb_audio_probe(struct usb_device *dev,
                         goto __error;
         }
 
-        chip->ctrl_intf = alts;
+        /*
+         * For devices with more than one control interface, we assume the
+         * first contains the audio controls. We might need a more specific
+         * check here in the future.
+         */
+        if (!chip->ctrl_intf)
+                chip->ctrl_intf = alts;
 
         if (err > 0) {
                 /* create normal USB audio interfaces */