ALSA: usb-audio: Clean up endpoint setups at PCM prepare

This patch cleans up the superfluous checks and calls for setting up
the endpoints at PCM prepare callback:

- Drop stop_endpoints() and sync_pending_stops() calls; the stream is
  guaranteed to have been already stopped and synced at each PCM
  prepare call by ALSA PCM core

- Call snd_usb_endpoint_prepare() unconditionally;
  the check for endpoint->need_setup is done in
  snd_pcm_hw_endpoint_prepare() itself

- Apply snd_usb_set_format_quirk() only when the endpoint is actually
  set up (i.e. the return code from snd_usb_endpoint_prepare() > 0)

- Move a few lines back into snd_usb_pcm_prepare();
  it's even easier to follow than a small useless function

Link: https://lore.kernel.org/r/20220901130831.6136-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index b604f7e95e8295848ba140ec350eb3ef2afaaa5d..4ed53a3dc922ab714336341e42819b8cc89b48c2 100644 (file)
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -433,35 +433,6 @@ static void close_endpoints(struct snd_usb_audio *chip,
        }
 }
 
-static int configure_endpoints(struct snd_usb_audio *chip,
-                              struct snd_usb_substream *subs)
-{
-       int err;
-
-       if (subs->data_endpoint->need_setup) {
-               /* stop any running stream beforehand */
-               if (stop_endpoints(subs, false))
-                       sync_pending_stops(subs);
-               if (subs->sync_endpoint) {
-                       err = snd_usb_endpoint_prepare(chip, subs->sync_endpoint);
-                       if (err < 0)
-                               return err;
-               }
-               err = snd_usb_endpoint_prepare(chip, subs->data_endpoint);
-               if (err < 0)
-                       return err;
-               snd_usb_set_format_quirk(subs, subs->cur_audiofmt);
-       } else {
-               if (subs->sync_endpoint) {
-                       err = snd_usb_endpoint_prepare(chip, subs->sync_endpoint);
-                       if (err < 0)
-                               return err;
-               }
-       }
-
-       return 0;
-}
-
 /*
  * hw_params callback
  *
@@ -640,9 +611,18 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
                goto unlock;
        }
 
-       ret = configure_endpoints(chip, subs);
+       if (subs->sync_endpoint) {
+               ret = snd_usb_endpoint_prepare(chip, subs->sync_endpoint);
+               if (ret < 0)
+                       goto unlock;
+       }
+
+       ret = snd_usb_endpoint_prepare(chip, subs->data_endpoint);
        if (ret < 0)
                goto unlock;
+       else if (ret > 0)
+               snd_usb_set_format_quirk(subs, subs->cur_audiofmt);
+       ret = 0;
 
        /* reset the pointer */
        subs->buffer_bytes = frames_to_bytes(runtime, runtime->buffer_size);