ALSA: pcm: Unify playback and capture poll callbacks

The poll callbacks for playback and capture directions are doing
fairly similar but with a slight difference.  This patch unifies the
two functions into a single callback.  The advantage of this
refactoring is that the direction-specific procedures become clearer.

There should be no functional change but only the code cleanup.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index f69d89c..eddb0cd 100644 (file)
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3095,82 +3095,46 @@ static ssize_t snd_pcm_writev(struct kiocb *iocb, struct iov_iter *from)
        return result;
 }
 
-static __poll_t snd_pcm_playback_poll(struct file *file, poll_table * wait)
+static __poll_t snd_pcm_poll(struct file *file, poll_table *wait)
 {
        struct snd_pcm_file *pcm_file;
        struct snd_pcm_substream *substream;
        struct snd_pcm_runtime *runtime;
-        __poll_t mask;
+       __poll_t mask, ok;
        snd_pcm_uframes_t avail;
 
        pcm_file = file->private_data;
 
        substream = pcm_file->substream;
+       if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+               ok = EPOLLOUT | EPOLLWRNORM;
+       else
+               ok = EPOLLIN | EPOLLRDNORM;
        if (PCM_RUNTIME_CHECK(substream))
-               return EPOLLOUT | EPOLLWRNORM | EPOLLERR;
-       runtime = substream->runtime;
-
-       poll_wait(file, &runtime->sleep, wait);
-
-       snd_pcm_stream_lock_irq(substream);
-       avail = snd_pcm_playback_avail(runtime);
-       switch (runtime->status->state) {
-       case SNDRV_PCM_STATE_RUNNING:
-       case SNDRV_PCM_STATE_PREPARED:
-       case SNDRV_PCM_STATE_PAUSED:
-               if (avail >= runtime->control->avail_min) {
-                       mask = EPOLLOUT | EPOLLWRNORM;
-                       break;
-               }
-               /* Fall through */
-       case SNDRV_PCM_STATE_DRAINING:
-               mask = 0;
-               break;
-       default:
-               mask = EPOLLOUT | EPOLLWRNORM | EPOLLERR;
-               break;
-       }
-       snd_pcm_stream_unlock_irq(substream);
-       return mask;
-}
-
-static __poll_t snd_pcm_capture_poll(struct file *file, poll_table * wait)
-{
-       struct snd_pcm_file *pcm_file;
-       struct snd_pcm_substream *substream;
-       struct snd_pcm_runtime *runtime;
-        __poll_t mask;
-       snd_pcm_uframes_t avail;
+               return ok | EPOLLERR;
 
-       pcm_file = file->private_data;
-
-       substream = pcm_file->substream;
-       if (PCM_RUNTIME_CHECK(substream))
-               return EPOLLIN | EPOLLRDNORM | EPOLLERR;
        runtime = substream->runtime;
-
        poll_wait(file, &runtime->sleep, wait);
 
+       mask = 0;
        snd_pcm_stream_lock_irq(substream);
-       avail = snd_pcm_capture_avail(runtime);
+       avail = snd_pcm_avail(substream);
        switch (runtime->status->state) {
        case SNDRV_PCM_STATE_RUNNING:
        case SNDRV_PCM_STATE_PREPARED:
        case SNDRV_PCM_STATE_PAUSED:
-               if (avail >= runtime->control->avail_min) {
-                       mask = EPOLLIN | EPOLLRDNORM;
-                       break;
-               }
-               mask = 0;
+               if (avail >= runtime->control->avail_min)
+                       mask = ok;
                break;
        case SNDRV_PCM_STATE_DRAINING:
-               if (avail > 0) {
-                       mask = EPOLLIN | EPOLLRDNORM;
-                       break;
+               if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
+                       mask = ok;
+                       if (!avail)
+                               mask |= EPOLLERR;
                }
-               /* Fall through */
+               break;
        default:
-               mask = EPOLLIN | EPOLLRDNORM | EPOLLERR;
+               mask = ok | EPOLLERR;
                break;
        }
        snd_pcm_stream_unlock_irq(substream);
@@ -3662,7 +3626,7 @@ const struct file_operations snd_pcm_f_ops[2] = {
                .open =                 snd_pcm_playback_open,
                .release =              snd_pcm_release,
                .llseek =               no_llseek,
-               .poll =                 snd_pcm_playback_poll,
+               .poll =                 snd_pcm_poll,
                .unlocked_ioctl =       snd_pcm_ioctl,
                .compat_ioctl =         snd_pcm_ioctl_compat,
                .mmap =                 snd_pcm_mmap,
@@ -3676,7 +3640,7 @@ const struct file_operations snd_pcm_f_ops[2] = {
                .open =                 snd_pcm_capture_open,
                .release =              snd_pcm_release,
                .llseek =               no_llseek,
-               .poll =                 snd_pcm_capture_poll,
+               .poll =                 snd_pcm_poll,
                .unlocked_ioctl =       snd_pcm_ioctl,
                .compat_ioctl =         snd_pcm_ioctl_compat,
                .mmap =                 snd_pcm_mmap,