ALSA: pcm: Simplify forward/rewind codes

Factor out the common codes in snd_pcm_*_forward() and *_rewind()
functions to simplify the codes.  No functional changes.

Reviewd-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 93bd2c6..ecde57a 100644 (file)
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -2455,34 +2455,58 @@ static int do_pcm_hwsync(struct snd_pcm_substream *substream)
        }
 }
 
+/* increase the appl_ptr; returns the processed frames */
+static snd_pcm_sframes_t forward_appl_ptr(struct snd_pcm_substream *substream,
+                                         snd_pcm_uframes_t frames,
+                                          snd_pcm_sframes_t avail)
+{
+       struct snd_pcm_runtime *runtime = substream->runtime;
+       snd_pcm_sframes_t appl_ptr;
+
+       if (avail <= 0)
+               return 0;
+       if (frames > (snd_pcm_uframes_t)avail)
+               frames = avail;
+       appl_ptr = runtime->control->appl_ptr + frames;
+       if (appl_ptr >= (snd_pcm_sframes_t)runtime->boundary)
+               appl_ptr -= runtime->boundary;
+       runtime->control->appl_ptr = appl_ptr;
+       return frames;
+}
+
+/* decrease the appl_ptr; returns the processed frames */
+static snd_pcm_sframes_t rewind_appl_ptr(struct snd_pcm_substream *substream,
+                                        snd_pcm_uframes_t frames,
+                                        snd_pcm_sframes_t avail)
+{
+       struct snd_pcm_runtime *runtime = substream->runtime;
+       snd_pcm_sframes_t appl_ptr;
+
+       if (avail <= 0)
+               return 0;
+       if (frames > (snd_pcm_uframes_t)avail)
+               frames = avail;
+       appl_ptr = runtime->control->appl_ptr - frames;
+       if (appl_ptr < 0)
+               appl_ptr += runtime->boundary;
+       runtime->control->appl_ptr = appl_ptr;
+       return frames;
+}
+
 static snd_pcm_sframes_t snd_pcm_playback_rewind(struct snd_pcm_substream *substream,
                                                 snd_pcm_uframes_t frames)
 {
        struct snd_pcm_runtime *runtime = substream->runtime;
-       snd_pcm_sframes_t appl_ptr;
        snd_pcm_sframes_t ret;
-       snd_pcm_sframes_t hw_avail;
 
        if (frames == 0)
                return 0;
 
        snd_pcm_stream_lock_irq(substream);
        ret = do_pcm_hwsync(substream);
-       if (ret < 0)
-               goto __end;
-       hw_avail = snd_pcm_playback_hw_avail(runtime);
-       if (hw_avail <= 0) {
-               ret = 0;
-               goto __end;
-       }
-       if (frames > (snd_pcm_uframes_t)hw_avail)
-               frames = hw_avail;
-       appl_ptr = runtime->control->appl_ptr - frames;
-       if (appl_ptr < 0)
-               appl_ptr += runtime->boundary;
-       runtime->control->appl_ptr = appl_ptr;
-       ret = frames;
- __end:
+       if (!ret)
+               ret = rewind_appl_ptr(substream, frames,
+                                     snd_pcm_playback_hw_avail(runtime));
        snd_pcm_stream_unlock_irq(substream);
        return ret;
 }
@@ -2491,30 +2515,16 @@ static snd_pcm_sframes_t snd_pcm_capture_rewind(struct snd_pcm_substream *substr
                                                snd_pcm_uframes_t frames)
 {
        struct snd_pcm_runtime *runtime = substream->runtime;
-       snd_pcm_sframes_t appl_ptr;
        snd_pcm_sframes_t ret;
-       snd_pcm_sframes_t hw_avail;
 
        if (frames == 0)
                return 0;
 
        snd_pcm_stream_lock_irq(substream);
        ret = do_pcm_hwsync(substream);
-       if (ret < 0)
-               goto __end;
-       hw_avail = snd_pcm_capture_hw_avail(runtime);
-       if (hw_avail <= 0) {
-               ret = 0;
-               goto __end;
-       }
-       if (frames > (snd_pcm_uframes_t)hw_avail)
-               frames = hw_avail;
-       appl_ptr = runtime->control->appl_ptr - frames;
-       if (appl_ptr < 0)
-               appl_ptr += runtime->boundary;
-       runtime->control->appl_ptr = appl_ptr;
-       ret = frames;
- __end:
+       if (!ret)
+               ret = rewind_appl_ptr(substream, frames,
+                                     snd_pcm_capture_hw_avail(runtime));
        snd_pcm_stream_unlock_irq(substream);
        return ret;
 }
@@ -2523,30 +2533,16 @@ static snd_pcm_sframes_t snd_pcm_playback_forward(struct snd_pcm_substream *subs
                                                  snd_pcm_uframes_t frames)
 {
        struct snd_pcm_runtime *runtime = substream->runtime;
-       snd_pcm_sframes_t appl_ptr;
        snd_pcm_sframes_t ret;
-       snd_pcm_sframes_t avail;
 
        if (frames == 0)
                return 0;
 
        snd_pcm_stream_lock_irq(substream);
        ret = do_pcm_hwsync(substream);
-       if (ret < 0)
-               goto __end;
-       avail = snd_pcm_playback_avail(runtime);
-       if (avail <= 0) {
-               ret = 0;
-               goto __end;
-       }
-       if (frames > (snd_pcm_uframes_t)avail)
-               frames = avail;
-       appl_ptr = runtime->control->appl_ptr + frames;
-       if (appl_ptr >= (snd_pcm_sframes_t)runtime->boundary)
-               appl_ptr -= runtime->boundary;
-       runtime->control->appl_ptr = appl_ptr;
-       ret = frames;
- __end:
+       if (!ret)
+               ret = forward_appl_ptr(substream, frames,
+                                      snd_pcm_playback_avail(runtime));
        snd_pcm_stream_unlock_irq(substream);
        return ret;
 }
@@ -2555,30 +2551,16 @@ static snd_pcm_sframes_t snd_pcm_capture_forward(struct snd_pcm_substream *subst
                                                 snd_pcm_uframes_t frames)
 {
        struct snd_pcm_runtime *runtime = substream->runtime;
-       snd_pcm_sframes_t appl_ptr;
        snd_pcm_sframes_t ret;
-       snd_pcm_sframes_t avail;
 
        if (frames == 0)
                return 0;
 
        snd_pcm_stream_lock_irq(substream);
        ret = do_pcm_hwsync(substream);
-       if (ret < 0)
-               goto __end;
-       avail = snd_pcm_capture_avail(runtime);
-       if (avail <= 0) {
-               ret = 0;
-               goto __end;
-       }
-       if (frames > (snd_pcm_uframes_t)avail)
-               frames = avail;
-       appl_ptr = runtime->control->appl_ptr + frames;
-       if (appl_ptr >= (snd_pcm_sframes_t)runtime->boundary)
-               appl_ptr -= runtime->boundary;
-       runtime->control->appl_ptr = appl_ptr;
-       ret = frames;
- __end:
+       if (!ret)
+               ret = forward_appl_ptr(substream, frames,
+                                      snd_pcm_capture_avail(runtime));
        snd_pcm_stream_unlock_irq(substream);
        return ret;
 }