ALSA: pcm: Use a common helper for PCM state check and hwsync

The mostly same codes for checking the current PCM state and calling
hwsync are found in a few places.  This patch simplifies them by
creating a common helper function.

It also fixes a couple of cases where we missed the proper state check
(e.g. PAUSED state wasn't handled in rewind and snd_pcm_hwsync()),
too.
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/pcm_native.c

@@ -2431,6 +2431,30 @@ static int snd_pcm_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+/* check and update PCM state; return 0 or a negative error
+ * call this inside PCM lock
+ */
+static int do_pcm_hwsync(struct snd_pcm_substream *substream)
+{
+	switch (substream->runtime->status->state) {
+	case SNDRV_PCM_STATE_DRAINING:
+		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+			return -EBADFD;
+		/* Fall through */
+	case SNDRV_PCM_STATE_RUNNING:
+		return snd_pcm_update_hw_ptr(substream);
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
+		return 0;
+	case SNDRV_PCM_STATE_SUSPENDED:
+		return -ESTRPIPE;
+	case SNDRV_PCM_STATE_XRUN:
+		return -EPIPE;
+	default:
+		return -EBADFD;
+	}
+}
+
 static snd_pcm_sframes_t snd_pcm_playback_rewind(struct snd_pcm_substream *substream,
 						 snd_pcm_uframes_t frames)
 {
@@ -2443,25 +2467,9 @@ static snd_pcm_sframes_t snd_pcm_playback_rewind(struct snd_pcm_substream *subst
 		return 0;
 
 	snd_pcm_stream_lock_irq(substream);
-	switch (runtime->status->state) {
-	case SNDRV_PCM_STATE_PREPARED:
-		break;
-	case SNDRV_PCM_STATE_DRAINING:
-	case SNDRV_PCM_STATE_RUNNING:
-		if (snd_pcm_update_hw_ptr(substream) >= 0)
-			break;
-		/* Fall through */
-	case SNDRV_PCM_STATE_XRUN:
-		ret = -EPIPE;
-		goto __end;
-	case SNDRV_PCM_STATE_SUSPENDED:
-		ret = -ESTRPIPE;
+	ret = do_pcm_hwsync(substream);
+	if (ret < 0)
 		goto __end;
-	default:
-		ret = -EBADFD;
-		goto __end;
-	}
-
 	hw_avail = snd_pcm_playback_hw_avail(runtime);
 	if (hw_avail <= 0) {
 		ret = 0;
@@ -2491,25 +2499,9 @@ static snd_pcm_sframes_t snd_pcm_capture_rewind(struct snd_pcm_substream *substr
 		return 0;
 
 	snd_pcm_stream_lock_irq(substream);
-	switch (runtime->status->state) {
-	case SNDRV_PCM_STATE_PREPARED:
-	case SNDRV_PCM_STATE_DRAINING:
-		break;
-	case SNDRV_PCM_STATE_RUNNING:
-		if (snd_pcm_update_hw_ptr(substream) >= 0)
-			break;
-		/* Fall through */
-	case SNDRV_PCM_STATE_XRUN:
-		ret = -EPIPE;
-		goto __end;
-	case SNDRV_PCM_STATE_SUSPENDED:
-		ret = -ESTRPIPE;
+	ret = do_pcm_hwsync(substream);
+	if (ret < 0)
 		goto __end;
-	default:
-		ret = -EBADFD;
-		goto __end;
-	}
-
 	hw_avail = snd_pcm_capture_hw_avail(runtime);
 	if (hw_avail <= 0) {
 		ret = 0;
@@ -2539,26 +2531,9 @@ static snd_pcm_sframes_t snd_pcm_playback_forward(struct snd_pcm_substream *subs
 		return 0;
 
 	snd_pcm_stream_lock_irq(substream);
-	switch (runtime->status->state) {
-	case SNDRV_PCM_STATE_PREPARED:
-	case SNDRV_PCM_STATE_PAUSED:
-		break;
-	case SNDRV_PCM_STATE_DRAINING:
-	case SNDRV_PCM_STATE_RUNNING:
-		if (snd_pcm_update_hw_ptr(substream) >= 0)
-			break;
-		/* Fall through */
-	case SNDRV_PCM_STATE_XRUN:
-		ret = -EPIPE;
+	ret = do_pcm_hwsync(substream);
+	if (ret < 0)
 		goto __end;
-	case SNDRV_PCM_STATE_SUSPENDED:
-		ret = -ESTRPIPE;
-		goto __end;
-	default:
-		ret = -EBADFD;
-		goto __end;
-	}
-
 	avail = snd_pcm_playback_avail(runtime);
 	if (avail <= 0) {
 		ret = 0;
@@ -2588,26 +2563,9 @@ static snd_pcm_sframes_t snd_pcm_capture_forward(struct snd_pcm_substream *subst
 		return 0;
 
 	snd_pcm_stream_lock_irq(substream);
-	switch (runtime->status->state) {
-	case SNDRV_PCM_STATE_PREPARED:
-	case SNDRV_PCM_STATE_DRAINING:
-	case SNDRV_PCM_STATE_PAUSED:
-		break;
-	case SNDRV_PCM_STATE_RUNNING:
-		if (snd_pcm_update_hw_ptr(substream) >= 0)
-			break;
-		/* Fall through */
-	case SNDRV_PCM_STATE_XRUN:
-		ret = -EPIPE;
-		goto __end;
-	case SNDRV_PCM_STATE_SUSPENDED:
-		ret = -ESTRPIPE;
+	ret = do_pcm_hwsync(substream);
+	if (ret < 0)
 		goto __end;
-	default:
-		ret = -EBADFD;
-		goto __end;
-	}
-
 	avail = snd_pcm_capture_avail(runtime);
 	if (avail <= 0) {
 		ret = 0;
@@ -2627,33 +2585,10 @@ static snd_pcm_sframes_t snd_pcm_capture_forward(struct snd_pcm_substream *subst
 
 static int snd_pcm_hwsync(struct snd_pcm_substream *substream)
 {
-	struct snd_pcm_runtime *runtime = substream->runtime;
 	int err;
 
 	snd_pcm_stream_lock_irq(substream);
-	switch (runtime->status->state) {
-	case SNDRV_PCM_STATE_DRAINING:
-		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
-			goto __badfd;
-		/* Fall through */
-	case SNDRV_PCM_STATE_RUNNING:
-		if ((err = snd_pcm_update_hw_ptr(substream)) < 0)
-			break;
-		/* Fall through */
-	case SNDRV_PCM_STATE_PREPARED:
-		err = 0;
-		break;
-	case SNDRV_PCM_STATE_SUSPENDED:
-		err = -ESTRPIPE;
-		break;
-	case SNDRV_PCM_STATE_XRUN:
-		err = -EPIPE;
-		break;
-	default:
-	      __badfd:
-		err = -EBADFD;
-		break;
-	}
+	err = do_pcm_hwsync(substream);
 	snd_pcm_stream_unlock_irq(substream);
 	return err;
 }
@@ -2666,31 +2601,13 @@ static int snd_pcm_delay(struct snd_pcm_substream *substream,
 	snd_pcm_sframes_t n = 0;
 
 	snd_pcm_stream_lock_irq(substream);
-	switch (runtime->status->state) {
-	case SNDRV_PCM_STATE_DRAINING:
-		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
-			goto __badfd;
-		/* Fall through */
-	case SNDRV_PCM_STATE_RUNNING:
-		if ((err = snd_pcm_update_hw_ptr(substream)) < 0)
-			break;
-		/* Fall through */
-	case SNDRV_PCM_STATE_PREPARED:
-	case SNDRV_PCM_STATE_SUSPENDED:
-		err = 0;
+	err = do_pcm_hwsync(substream);
+	if (!err) {
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			n = snd_pcm_playback_hw_avail(runtime);
 		else
 			n = snd_pcm_capture_avail(runtime);
 		n += runtime->delay;
-		break;
-	case SNDRV_PCM_STATE_XRUN:
-		err = -EPIPE;
-		break;
-	default:
-	      __badfd:
-		err = -EBADFD;
-		break;
 	}
 	snd_pcm_stream_unlock_irq(substream);
 	if (!err)