[alsa-devel] [PATCH 1/2] ASoC: dpcm: rework runtime stream merge

[Jerome Brunet]

The goal of this patch is to simplify a bit dpcm runtime stream merge
by removing several local variables.

ATM, merge functions return the BE 'filter' values which should then be
filtered against the FE stream values. This create a lot of local
variable and unnecessary init of min and max.

Instead of this, we can pass the FE stream values directly and let the
BE filtering functions perform the merge 'in-place'

Signed-off-by: Jerome Brunet <jbrunet at baylibre.com>
---
 sound/soc/soc-pcm.c | 39 +++++++++++++++------------------------
 1 file changed, 15 insertions(+), 24 deletions(-)

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index b959af4cff3a..54141a69b6b0 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -1672,29 +1672,28 @@ int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream)
 }
 
 static void dpcm_init_runtime_hw(struct snd_pcm_runtime *runtime,
-				 struct snd_soc_pcm_stream *stream,
-				 u64 formats)
+				 struct snd_soc_pcm_stream *stream)
 {
 	runtime->hw.rate_min = stream->rate_min;
 	runtime->hw.rate_max = stream->rate_max;
 	runtime->hw.channels_min = stream->channels_min;
 	runtime->hw.channels_max = stream->channels_max;
 	if (runtime->hw.formats)
-		runtime->hw.formats &= formats & stream->formats;
+		runtime->hw.formats &= stream->formats;
 	else
-		runtime->hw.formats = formats & stream->formats;
+		runtime->hw.formats = stream->formats;
 	runtime->hw.rates = stream->rates;
 }
 
-static u64 dpcm_runtime_base_format(struct snd_pcm_substream *substream)
+static void dpcm_runtime_merge_format(struct snd_pcm_substream *substream,
+				      u64 *formats)
 {
 	struct snd_soc_pcm_runtime *fe = substream->private_data;
 	struct snd_soc_dpcm *dpcm;
-	u64 formats = ULLONG_MAX;
 	int stream = substream->stream;
 
 	if (!fe->dai_link->dpcm_merged_format)
-		return formats;
+		return;
 
 	/*
 	 * It returns merged BE codec format
@@ -1722,16 +1721,14 @@ static u64 dpcm_runtime_base_format(struct snd_pcm_substream *substream)
 			else
 				codec_stream = &codec_dai_drv->capture;
 
-			formats &= codec_stream->formats;
+			*formats &= codec_stream->formats;
 		}
 	}
-
-	return formats;
 }
 
-static void dpcm_runtime_base_chan(struct snd_pcm_substream *substream,
-				   unsigned int *channels_min,
-				   unsigned int *channels_max)
+static void dpcm_runtime_merge_chan(struct snd_pcm_substream *substream,
+				    unsigned int *channels_min,
+				    unsigned int *channels_max)
 {
 	struct snd_soc_pcm_runtime *fe = substream->private_data;
 	struct snd_soc_dpcm *dpcm;
@@ -1740,9 +1737,6 @@ static void dpcm_runtime_base_chan(struct snd_pcm_substream *substream,
 	if (!fe->dai_link->dpcm_merged_chan)
 		return;
 
-	*channels_min = 0;
-	*channels_max = UINT_MAX;
-
 	/*
 	 * It returns merged BE codec channel;
 	 * if FE want to use it (= dpcm_merged_chan)
@@ -1789,18 +1783,15 @@ static void dpcm_set_fe_runtime(struct snd_pcm_substream *substream)
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;
-	u64 format = dpcm_runtime_base_format(substream);
-	unsigned int channels_min = 0, channels_max = UINT_MAX;
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->playback, format);
+		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->playback);
 	else
-		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->capture, format);
-
-	dpcm_runtime_base_chan(substream, &channels_min, &channels_max);
+		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->capture);
 
-	runtime->hw.channels_min = max(channels_min, runtime->hw.channels_min);
-	runtime->hw.channels_max = min(channels_max, runtime->hw.channels_max);
+	dpcm_runtime_merge_format(substream, &runtime->hw.formats);
+	dpcm_runtime_merge_chan(substream, &runtime->hw.channels_min,
+				&runtime->hw.channels_max);
 }
 
 static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd);
-- 
2.14.4