ALSA: usb-audio: remove is_playback from implicit feedback quirks

An implicit feedback endpoint can only be a capture source. The
consumer (sink) of the implicit feedback endpoint is therefore limited
to playback EPs.
Check if the target endpoint is a playback first and remove redundant
checks.

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

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index bb2e0f52e92f428b3fa574e81cd5064e500e8f22..af30e08e3d3b7ec6cf587f2c4897f2febbb1c6c8 100644 (file)
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -334,41 +334,39 @@ static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
 {
        struct usb_host_interface *alts;
        struct usb_interface *iface;
-       int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
        int implicit_fb = 0;
        unsigned int ep;
 
+       /* Implicit feedback sync EPs consumers are always playback EPs */
+       if (subs->direction != SNDRV_PCM_STREAM_PLAYBACK)
+               return 0;
+
        switch (subs->stream->chip->usb_id) {
        case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
        case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
-               if (is_playback) {
-                       implicit_fb = 1;
-                       ep = 0x81;
-                       iface = usb_ifnum_to_if(dev, 3);
+               implicit_fb = 1;
+               ep = 0x81;
+               iface = usb_ifnum_to_if(dev, 3);
 
-                       if (!iface || iface->num_altsetting == 0)
-                               return -EINVAL;
+               if (!iface || iface->num_altsetting == 0)
+                       return -EINVAL;
 
-                       alts = &iface->altsetting[1];
-                       goto add_sync_ep;
-               }
+               alts = &iface->altsetting[1];
+               goto add_sync_ep;
                break;
        case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
        case USB_ID(0x0763, 0x2081):
-               if (is_playback) {
-                       implicit_fb = 1;
-                       ep = 0x81;
-                       iface = usb_ifnum_to_if(dev, 2);
+               implicit_fb = 1;
+               ep = 0x81;
+               iface = usb_ifnum_to_if(dev, 2);
 
-                       if (!iface || iface->num_altsetting == 0)
-                               return -EINVAL;
+               if (!iface || iface->num_altsetting == 0)
+                       return -EINVAL;
 
-                       alts = &iface->altsetting[1];
-                       goto add_sync_ep;
-               }
+               alts = &iface->altsetting[1];
+               goto add_sync_ep;
        }
-       if (is_playback &&
-           attr == USB_ENDPOINT_SYNC_ASYNC &&
+       if (attr == USB_ENDPOINT_SYNC_ASYNC &&
            altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
            altsd->bInterfaceProtocol == 2 &&
            altsd->bNumEndpoints == 1 &&