1 files changed, 47 insertions, 1 deletions

diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
index d018e96..6b40bdb 100644
--- a/sound/soc/omap/omap-mcbsp.c
+++ b/sound/soc/omap/omap-mcbsp.c
@@ -157,6 +157,17 @@ static void omap_mcbsp_dai_shutdown(struct snd_pcm_substream *substream,
 				    struct snd_soc_dai *cpu_dai)
 {
 	struct omap_mcbsp *mcbsp = snd_soc_dai_get_drvdata(cpu_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;
+
+	if (mcbsp->latency[stream2])
+		pm_qos_update_request(&mcbsp->pm_qos_req,
+				      mcbsp->latency[stream2]);
+	else if (mcbsp->latency[stream1])
+		pm_qos_remove_request(&mcbsp->pm_qos_req);
+
+	mcbsp->latency[stream1] = 0;
 
 	if (!cpu_dai->active) {
 		omap_mcbsp_free(mcbsp);
@@ -164,6 +175,28 @@ static void omap_mcbsp_dai_shutdown(struct snd_pcm_substream *substream,
 	}
 }
 
+static int omap_mcbsp_dai_prepare(struct snd_pcm_substream *substream,
+				  struct snd_soc_dai *cpu_dai)
+{
+	struct omap_mcbsp *mcbsp = snd_soc_dai_get_drvdata(cpu_dai);
+	struct pm_qos_request *pm_qos_req = &mcbsp->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 = mcbsp->latency[stream2];
+
+	/* Prevent omap hardware from hitting off between FIFO fills */
+	if (!latency || mcbsp->latency[stream1] < latency)
+		latency = mcbsp->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);
+
+	return 0;
+}
+
 static int omap_mcbsp_dai_trigger(struct snd_pcm_substream *substream, int cmd,
 				  struct snd_soc_dai *cpu_dai)
 {
@@ -226,6 +259,7 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream,
 	int wlen, channels, wpf;
 	int pkt_size = 0;
 	unsigned int format, div, framesize, master;
+	unsigned int buffer_size = mcbsp->pdata->buffer_size;
 
 	dma_data = snd_soc_dai_get_dma_data(cpu_dai, substream);
 	channels = params_channels(params);
@@ -240,7 +274,9 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream,
 	default:
 		return -EINVAL;
 	}
-	if (mcbsp->pdata->buffer_size) {
+	if (buffer_size) {
+		int latency;
+
 		if (mcbsp->dma_op_mode == MCBSP_DMA_MODE_THRESHOLD) {
 			int period_words, max_thrsh;
 			int divider = 0;
@@ -271,6 +307,12 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream,
 			/* Use packet mode for non mono streams */
 			pkt_size = channels;
 		}
+
+		latency = ((((buffer_size - pkt_size) / channels) * 1000)
+				 / (params->rate_num / params->rate_den));
+
+		mcbsp->latency[substream->stream] = latency;
+
 		omap_mcbsp_set_threshold(substream, pkt_size);
 	}
 
@@ -554,6 +596,7 @@ static int omap_mcbsp_dai_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
 static const struct snd_soc_dai_ops mcbsp_dai_ops = {
 	.startup	= omap_mcbsp_dai_startup,
 	.shutdown	= omap_mcbsp_dai_shutdown,
+	.prepare	= omap_mcbsp_dai_prepare,
 	.trigger	= omap_mcbsp_dai_trigger,
 	.delay		= omap_mcbsp_dai_delay,
 	.hw_params	= omap_mcbsp_dai_hw_params,
@@ -835,6 +878,9 @@ static int asoc_mcbsp_remove(struct platform_device *pdev)
 	if (mcbsp->pdata->ops && mcbsp->pdata->ops->free)
 		mcbsp->pdata->ops->free(mcbsp->id);
 
+	if (pm_qos_request_active(&mcbsp->pm_qos_req))
+		pm_qos_remove_request(&mcbsp->pm_qos_req);
+
 	omap_mcbsp_cleanup(mcbsp);
 
 	clk_put(mcbsp->fclk);