ALSA: pcm: Minor refactoring in snd_pcm_attach_substream()

No functional changes at all.

Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 0345e53..d63d262 100644 (file)
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -919,6 +919,9 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 
        if (snd_BUG_ON(!pcm || !rsubstream))
                return -ENXIO;
+       if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
+                      stream != SNDRV_PCM_STREAM_CAPTURE))
+               return -EINVAL;
        *rsubstream = NULL;
        pstr = &pcm->streams[stream];
        if (pstr->substream == NULL || pstr->substream_count == 0)
@@ -927,25 +930,14 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
        card = pcm->card;
        prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 
-       switch (stream) {
-       case SNDRV_PCM_STREAM_PLAYBACK:
-               if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
-                       for (substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; substream; substream = substream->next) {
-                               if (SUBSTREAM_BUSY(substream))
-                                       return -EAGAIN;
-                       }
-               }
-               break;
-       case SNDRV_PCM_STREAM_CAPTURE:
-               if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
-                       for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next) {
-                               if (SUBSTREAM_BUSY(substream))
-                                       return -EAGAIN;
-                       }
+       if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
+               int opposite = !stream;
+
+               for (substream = pcm->streams[opposite].substream; substream;
+                    substream = substream->next) {
+                       if (SUBSTREAM_BUSY(substream))
+                               return -EAGAIN;
                }
-               break;
-       default:
-               return -EINVAL;
        }
 
        if (file->f_flags & O_APPEND) {
@@ -968,15 +960,12 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
                return 0;
        }
 
-       if (prefer_subdevice >= 0) {
-               for (substream = pstr->substream; substream; substream = substream->next)
-                       if (!SUBSTREAM_BUSY(substream) && substream->number == prefer_subdevice)
-                               goto __ok;
-       }
-       for (substream = pstr->substream; substream; substream = substream->next)
-               if (!SUBSTREAM_BUSY(substream))
+       for (substream = pstr->substream; substream; substream = substream->next) {
+               if (!SUBSTREAM_BUSY(substream) &&
+                   (prefer_subdevice == -1 ||
+                    substream->number == prefer_subdevice))
                        break;
-      __ok:
+       }
        if (substream == NULL)
                return -EAGAIN;