ASoC: omap-mcpdm: Add pm_qos handling to avoid under/overruns with CPU_IDLE (373a500e) · Commits · 戴 / test

sound/soc/omap/omap-mcpdm.c

+42 −1

Original line number	Diff line number	Diff line
		@@ -54,6 +54,8 @@ struct omap_mcpdm {
		unsigned long phys_base;
		void __iomem *io_base;
		int irq;
		struct pm_qos_request pm_qos_req;
		int latency[2];

		struct mutex mutex;

		@@ -277,6 +279,9 @@ static void omap_mcpdm_dai_shutdown(struct snd_pcm_substream *substream,
		struct snd_soc_dai *dai)
		{
		struct omap_mcpdm *mcpdm = snd_soc_dai_get_drvdata(dai);
		int tx = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
		int stream1 = tx ? SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE;
		int stream2 = tx ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;

		mutex_lock(&mcpdm->mutex);

		@@ -289,6 +294,14 @@ static void omap_mcpdm_dai_shutdown(struct snd_pcm_substream *substream,
		}
		}

		if (mcpdm->latency[stream2])
		pm_qos_update_request(&mcpdm->pm_qos_req,
		mcpdm->latency[stream2]);
		else if (mcpdm->latency[stream1])
		pm_qos_remove_request(&mcpdm->pm_qos_req);

		mcpdm->latency[stream1] = 0;

		mutex_unlock(&mcpdm->mutex);
		}

		@@ -300,7 +313,7 @@ static int omap_mcpdm_dai_hw_params(struct snd_pcm_substream *substream,
		int stream = substream->stream;
		struct snd_dmaengine_dai_dma_data *dma_data;
		u32 threshold;
		int channels;
		int channels, latency;
		int link_mask = 0;

		channels = params_channels(params);
		@@ -344,14 +357,25 @@ static int omap_mcpdm_dai_hw_params(struct snd_pcm_substream *substream,

		dma_data->maxburst =
		(MCPDM_DN_THRES_MAX - threshold) * channels;
		latency = threshold;
		} else {
		/* If playback is not running assume a stereo stream to come */
		if (!mcpdm->config[!stream].link_mask)
		mcpdm->config[!stream].link_mask = (0x3 << 3);

		dma_data->maxburst = threshold * channels;
		latency = (MCPDM_DN_THRES_MAX - threshold);
		}

		/*
		* The DMA must act to a DMA request within latency time (usec) to avoid
		* under/overflow
		*/
		mcpdm->latency[stream] = latency * USEC_PER_SEC / params_rate(params);

		if (!mcpdm->latency[stream])
		mcpdm->latency[stream] = 10;

		/* Check if we need to restart McPDM with this stream */
		if (mcpdm->config[stream].link_mask &&
		mcpdm->config[stream].link_mask != link_mask)
		@@ -366,6 +390,20 @@ static int omap_mcpdm_prepare(struct snd_pcm_substream *substream,
		struct snd_soc_dai *dai)
		{
		struct omap_mcpdm *mcpdm = snd_soc_dai_get_drvdata(dai);
		struct pm_qos_request *pm_qos_req = &mcpdm->pm_qos_req;
		int tx = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
		int stream1 = tx ? SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE;
		int stream2 = tx ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
		int latency = mcpdm->latency[stream2];

		/* Prevent omap hardware from hitting off between FIFO fills */
		if (!latency \|\| mcpdm->latency[stream1] < latency)
		latency = mcpdm->latency[stream1];

		if (pm_qos_request_active(pm_qos_req))
		pm_qos_update_request(pm_qos_req, latency);
		else if (latency)
		pm_qos_add_request(pm_qos_req, PM_QOS_CPU_DMA_LATENCY, latency);

		if (!omap_mcpdm_active(mcpdm)) {
		omap_mcpdm_start(mcpdm);
		@@ -427,6 +465,9 @@ static int omap_mcpdm_remove(struct snd_soc_dai *dai)
		free_irq(mcpdm->irq, (void *)mcpdm);
		pm_runtime_disable(mcpdm->dev);

		if (pm_qos_request_active(&mcpdm->pm_qos_req))
		pm_qos_remove_request(&mcpdm->pm_qos_req);

		return 0;
		}

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