[alsa-devel] Applied "ASoC: omap-dmic: Add pm_qos handling to avoid overruns with CPU_IDLE" to the asoc tree

[Mark Brown]

The patch

   ASoC: omap-dmic: Add pm_qos handling to avoid overruns with CPU_IDLE

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

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and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

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Thanks,
Mark

>From ffdcc3638c58d55a6fa68b6e5dfd4fb4109652eb Mon Sep 17 00:00:00 2001
From: Peter Ujfalusi <peter.ujfalusi at ti.com>
Date: Wed, 14 Nov 2018 13:06:23 +0200
Subject: [PATCH] ASoC: omap-dmic: Add pm_qos handling to avoid overruns with
 CPU_IDLE

We need to block sleep states which would require longer time to leave than
the time the DMA must react to the DMA request in order to keep the FIFO
serviced without overrun.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
Acked-by: Jarkko Nikula <jarkko.nikula at bitmer.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/omap/omap-dmic.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/sound/soc/omap/omap-dmic.c b/sound/soc/omap/omap-dmic.c
index fe966272bd0c..cba9645b6487 100644
--- a/sound/soc/omap/omap-dmic.c
+++ b/sound/soc/omap/omap-dmic.c
@@ -48,6 +48,8 @@ struct omap_dmic {
 	struct device *dev;
 	void __iomem *io_base;
 	struct clk *fclk;
+	struct pm_qos_request pm_qos_req;
+	int latency;
 	int fclk_freq;
 	int out_freq;
 	int clk_div;
@@ -124,6 +126,8 @@ static void omap_dmic_dai_shutdown(struct snd_pcm_substream *substream,
 
 	mutex_lock(&dmic->mutex);
 
+	pm_qos_remove_request(&dmic->pm_qos_req);
+
 	if (!dai->active)
 		dmic->active = 0;
 
@@ -228,6 +232,8 @@ static int omap_dmic_dai_hw_params(struct snd_pcm_substream *substream,
 	/* packet size is threshold * channels */
 	dma_data = snd_soc_dai_get_dma_data(dai, substream);
 	dma_data->maxburst = dmic->threshold * channels;
+	dmic->latency = (OMAP_DMIC_THRES_MAX - dmic->threshold) * USEC_PER_SEC /
+			params_rate(params);
 
 	return 0;
 }
@@ -238,6 +244,9 @@ static int omap_dmic_dai_prepare(struct snd_pcm_substream *substream,
 	struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);
 	u32 ctrl;
 
+	if (pm_qos_request_active(&dmic->pm_qos_req))
+		pm_qos_update_request(&dmic->pm_qos_req, dmic->latency);
+
 	/* Configure uplink threshold */
 	omap_dmic_write(dmic, OMAP_DMIC_FIFO_CTRL_REG, dmic->threshold);
 
-- 
2.19.1