[alsa-devel] [RFC PATCH] ASoC: compress: make BE and FE order inline with dpcm

[Srinivas Kandagatla]

For some reason order of startup/hw_params/prepare are reversed
in dynamic compress usecase when compared to dpcm usecase. This is
a issue with platforms like QCOM where it expects the BE to be
initialized before FE.

Interestingly the compress trigger callback order is inline with dpcm.

Am not 100% sure why the compress audio case has been reversed.
This patch is making the order inline with dpcm.

If the reverse ordering is just co-incendental then this change
makes sense and will avoid inventing some new mechanism to cope
with ordering.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla at linaro.org>
---
Hi All,

This patch is making the order of startup/hw_params/prepare in dynamic
compress usecase inline with dpcm case.

As I could not figure out the reason why this was done in reverse order.
So am sending this patch to get some insights of this.

It would be great If someone from Intel can test this patch to verify
if the new ordering is okay.

Without this patch, we have to come up with a new mechanism to enforce
ordering on QCom platform to get compress offload working.

Thanks,
Srini


 sound/soc/soc-compress.c | 96 +++++++++++++++++++++++-------------------------
 1 file changed, 46 insertions(+), 50 deletions(-)

diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
index b9e1673fea51..409d082e80d1 100644
--- a/sound/soc/soc-compress.c
+++ b/sound/soc/soc-compress.c
@@ -140,6 +140,30 @@ static int soc_compr_open_fe(struct snd_compr_stream *cstream)
 		stream = SNDRV_PCM_STREAM_CAPTURE;
 
 	mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
+	fe->dpcm[stream].runtime = fe_substream->runtime;
+
+	ret = dpcm_path_get(fe, stream, &list);
+	if (ret < 0)
+		goto be_err;
+	else if (ret == 0)
+		dev_dbg(fe->dev, "Compress ASoC: %s no valid %s route\n",
+			fe->dai_link->name, stream ? "capture" : "playback");
+	/* calculate valid and active FE <-> BE dpcms */
+	dpcm_process_paths(fe, stream, &list, 1);
+	fe->dpcm[stream].runtime = fe_substream->runtime;
+
+	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;
+
+	ret = dpcm_be_dai_startup(fe, stream);
+	if (ret < 0) {
+		/* clean up all links */
+		list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
+			dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
+
+		dpcm_be_disconnect(fe, stream);
+		fe->dpcm[stream].runtime = NULL;
+		goto out;
+	}
 
 	if (cpu_dai->driver->cops && cpu_dai->driver->cops->startup) {
 		ret = cpu_dai->driver->cops->startup(cstream, cpu_dai);
@@ -153,7 +177,7 @@ static int soc_compr_open_fe(struct snd_compr_stream *cstream)
 
 	ret = soc_compr_components_open(cstream, &component);
 	if (ret < 0)
-		goto machine_err;
+		goto open_err;
 
 	if (fe->dai_link->compr_ops && fe->dai_link->compr_ops->startup) {
 		ret = fe->dai_link->compr_ops->startup(cstream);
@@ -164,31 +188,6 @@ static int soc_compr_open_fe(struct snd_compr_stream *cstream)
 		}
 	}
 
-	fe->dpcm[stream].runtime = fe_substream->runtime;
-
-	ret = dpcm_path_get(fe, stream, &list);
-	if (ret < 0)
-		goto fe_err;
-	else if (ret == 0)
-		dev_dbg(fe->dev, "Compress ASoC: %s no valid %s route\n",
-			fe->dai_link->name, stream ? "capture" : "playback");
-
-	/* calculate valid and active FE <-> BE dpcms */
-	dpcm_process_paths(fe, stream, &list, 1);
-
-	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;
-
-	ret = dpcm_be_dai_startup(fe, stream);
-	if (ret < 0) {
-		/* clean up all links */
-		list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
-			dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
-
-		dpcm_be_disconnect(fe, stream);
-		fe->dpcm[stream].runtime = NULL;
-		goto path_err;
-	}
-
 	dpcm_clear_pending_state(fe, stream);
 	dpcm_path_put(&list);
 
@@ -201,17 +200,14 @@ static int soc_compr_open_fe(struct snd_compr_stream *cstream)
 
 	return 0;
 
-path_err:
-	dpcm_path_put(&list);
-fe_err:
-	if (fe->dai_link->compr_ops && fe->dai_link->compr_ops->shutdown)
-		fe->dai_link->compr_ops->shutdown(cstream);
 machine_err:
 	soc_compr_components_free(cstream, component);
-
+open_err:
 	if (cpu_dai->driver->cops && cpu_dai->driver->cops->shutdown)
 		cpu_dai->driver->cops->shutdown(cstream, cpu_dai);
 out:
+	dpcm_path_put(&list);
+be_err:
 	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
 	mutex_unlock(&fe->card->mutex);
 	return ret;
@@ -551,6 +547,24 @@ static int soc_compr_set_params_fe(struct snd_compr_stream *cstream,
 
 	mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
 
+	/*
+	 * Create an empty hw_params for the BE as the machine driver must
+	 * fix this up to match DSP decoder and ASRC configuration.
+	 * I.e. machine driver fixup for compressed BE is mandatory.
+	 */
+	memset(&fe->dpcm[fe_substream->stream].hw_params, 0,
+		sizeof(struct snd_pcm_hw_params));
+
+	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;
+
+	ret = dpcm_be_dai_hw_params(fe, stream);
+	if (ret < 0)
+		goto out;
+
+	ret = dpcm_be_dai_prepare(fe, stream);
+	if (ret < 0)
+		goto out;
+
 	if (cpu_dai->driver->cops && cpu_dai->driver->cops->set_params) {
 		ret = cpu_dai->driver->cops->set_params(cstream, params, cpu_dai);
 		if (ret < 0)
@@ -577,24 +591,6 @@ static int soc_compr_set_params_fe(struct snd_compr_stream *cstream,
 			goto out;
 	}
 
-	/*
-	 * Create an empty hw_params for the BE as the machine driver must
-	 * fix this up to match DSP decoder and ASRC configuration.
-	 * I.e. machine driver fixup for compressed BE is mandatory.
-	 */
-	memset(&fe->dpcm[fe_substream->stream].hw_params, 0,
-		sizeof(struct snd_pcm_hw_params));
-
-	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;
-
-	ret = dpcm_be_dai_hw_params(fe, stream);
-	if (ret < 0)
-		goto out;
-
-	ret = dpcm_be_dai_prepare(fe, stream);
-	if (ret < 0)
-		goto out;
-
 	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_START);
 	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_PREPARE;
 
-- 
2.16.2