linux-kernel - [PATCH 07/11] soundwire: intel: Only call sdw stream APIs for the first cpu

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Message-Id: <20200818024120.20721-8-yung-chuan.liao@linux.intel.com>
Date:   Tue, 18 Aug 2020 10:41:16 +0800
From:   Bard Liao <yung-chuan.liao@...ux.intel.com>
To:     alsa-devel@...a-project.org, vkoul@...nel.org
Cc:     vinod.koul@...aro.org, linux-kernel@...r.kernel.org, tiwai@...e.de,
        broonie@...nel.org, gregkh@...uxfoundation.org, jank@...ence.com,
        srinivas.kandagatla@...aro.org, rander.wang@...ux.intel.com,
        ranjani.sridharan@...ux.intel.com, hui.wang@...onical.com,
        pierre-louis.bossart@...ux.intel.com, sanyog.r.kale@...el.com,
        mengdong.lin@...el.com, bard.liao@...el.com
Subject: [PATCH 07/11] soundwire: intel: Only call sdw stream APIs for the first cpu_dai

We should call these APIs once per stream. So we can only call it
when the dai ops is invoked for the first cpu dai.

Signed-off-by: Bard Liao <yung-chuan.liao@...ux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@...ux.intel.com>
---
 drivers/soundwire/intel.c | 45 +++++++++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 6 deletions(-)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 89a8ad1f80e8..7c63581270fd 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -941,11 +941,13 @@ static int intel_hw_params(struct snd_pcm_substream *substream,
 static int intel_prepare(struct snd_pcm_substream *substream,
 			 struct snd_soc_dai *dai)
 {
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *first_cpu_dai = asoc_rtd_to_cpu(rtd, 0);
 	struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	struct sdw_cdns_dma_data *dma;
 	int ch, dir;
-	int ret;
+	int ret = 0;
 
 	dma = snd_soc_dai_get_dma_data(dai, substream);
 	if (!dma) {
@@ -985,7 +987,13 @@ static int intel_prepare(struct snd_pcm_substream *substream,
 			goto err;
 	}
 
-	ret = sdw_prepare_stream(dma->stream);
+	/*
+	 * All cpu dais belong to a stream. To ensure sdw_prepare_stream
+	 * is called once per stream, we should call it only when
+	 * dai = first_cpu_dai.
+	 */
+	if (first_cpu_dai == dai)
+		ret = sdw_prepare_stream(dma->stream);
 
 err:
 	return ret;
@@ -994,9 +1002,19 @@ static int intel_prepare(struct snd_pcm_substream *substream,
 static int intel_trigger(struct snd_pcm_substream *substream, int cmd,
 			 struct snd_soc_dai *dai)
 {
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *first_cpu_dai = asoc_rtd_to_cpu(rtd, 0);
 	struct sdw_cdns_dma_data *dma;
 	int ret;
 
+	/*
+	 * All cpu dais belong to a stream. To ensure sdw_enable/disable_stream
+	 * are called once per stream, we should call them only when
+	 * dai = first_cpu_dai.
+	 */
+	if (first_cpu_dai != dai)
+		return 0;
+
 	dma = snd_soc_dai_get_dma_data(dai, substream);
 	if (!dma) {
 		dev_err(dai->dev, "failed to get dma data in %s", __func__);
@@ -1031,6 +1049,8 @@ static int intel_trigger(struct snd_pcm_substream *substream, int cmd,
 static int
 intel_hw_free(struct snd_pcm_substream *substream, struct snd_soc_dai *dai)
 {
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *first_cpu_dai = asoc_rtd_to_cpu(rtd, 0);
 	struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	struct sdw_cdns_dma_data *dma;
@@ -1040,12 +1060,25 @@ intel_hw_free(struct snd_pcm_substream *substream, struct snd_soc_dai *dai)
 	if (!dma)
 		return -EIO;
 
-	ret = sdw_deprepare_stream(dma->stream);
-	if (ret) {
-		dev_err(dai->dev, "sdw_deprepare_stream: failed %d", ret);
-		return ret;
+	/*
+	 * All cpu dais belong to a stream. To ensure sdw_deprepare_stream
+	 * is called once per stream, we should call it only when
+	 * dai = first_cpu_dai.
+	 */
+	if (first_cpu_dai == dai) {
+		ret = sdw_deprepare_stream(dma->stream);
+		if (ret) {
+			dev_err(dai->dev, "sdw_deprepare_stream: failed %d", ret);
+			return ret;
+		}
 	}
 
+	/*
+	 * The sdw stream state will transition to RELEASED when stream->
+	 * master_list is empty. So the stream state will transition to
+	 * DEPREPARED for the first cpu-dai and to RELEASED for the last
+	 * cpu-dai.
+	 */
 	ret = sdw_stream_remove_master(&cdns->bus, dma->stream);
 	if (ret < 0) {
 		dev_err(dai->dev, "remove master from stream %s failed: %d\n",
-- 
2.17.1