ALSA: usb-audio: fix regression for fixed stream quirk

Commit 8f898e92aea2c24c7f379ee265d178f69ebb9c07 removed the redundant
reads of bInterfaceProtocol from the descriptors, but introduced a
regression to devices with quirks of type QUIRK_AUDIO_FIXED_ENDPOINT,
since fp->protocol is not set in setup process.

As a consequence, audio streams would not get initialized, as the
following logs show:

[   48.923043] setting usb interface 3:1
[   48.923056] Creating new capture data endpoint #81
[   48.923484] 4:3:1: cannot set freq 48000 to ep 0x81

This patch sets fp->protocol in create_fixed_stream_quirk() and
resolves the regression.

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 5b01330b8452..1bc45e71f1fe 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -129,6 +129,7 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
 {
         struct audioformat *fp;
         struct usb_host_interface *alts;
+        struct usb_interface_descriptor *altsd;
         int stream, err;
         unsigned *rate_table = NULL;
 
@@ -166,6 +167,9 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
                 return -EINVAL;
         }
         alts = &iface->altsetting[fp->altset_idx];
+        altsd = get_iface_desc(alts);
+        fp->protocol = altsd->bInterfaceProtocol;
+
         if (fp->datainterval == 0)
                 fp->datainterval = snd_usb_parse_datainterval(chip, alts);
         if (fp->maxpacksize == 0)