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>

1 files changed, 50 insertions, 68 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 93bd2c662c1d..ecde57afa45a 100644
--- 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;
 }