[PATCH v2 1/2] ASoC: adau17x1: Handling of DSP_RUN register during fw setup

[Robert Rosengren <robert.rosengren@axis.com>]

From: Danny Smith <dannys@axis.com>

DSP_RUN needs to be disabled during firmware write otherwise
we can end up with undefined behavior if writing to a dsp which
is already running firmware.

Signed-off-by: Danny Smith <dannys@axis.com>
Signed-off-by: Robert Rosengren <robert.rosengren@axis.com>
---
 sound/soc/codecs/adau17x1.c | 26 ++++++++++++++++++++------
 sound/soc/codecs/adau17x1.h |  3 ++-
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/sound/soc/codecs/adau17x1.c b/sound/soc/codecs/adau17x1.c
index 80c2a06285bb..12bf24c26818 100644
--- a/sound/soc/codecs/adau17x1.c
+++ b/sound/soc/codecs/adau17x1.c
@@ -502,7 +502,7 @@ static int adau17x1_hw_params(struct snd_pcm_substream *substream,
 	}
 
 	if (adau->sigmadsp) {
-		ret = adau17x1_setup_firmware(adau, params_rate(params));
+		ret = adau17x1_setup_firmware(component, params_rate(params));
 		if (ret < 0)
 			return ret;
 	}
@@ -835,26 +835,40 @@ bool adau17x1_volatile_register(struct device *dev, unsigned int reg)
 }
 EXPORT_SYMBOL_GPL(adau17x1_volatile_register);
 
-int adau17x1_setup_firmware(struct adau *adau, unsigned int rate)
+int adau17x1_setup_firmware(struct snd_soc_component *component,
+	unsigned int rate)
 {
 	int ret;
-	int dspsr;
+	int dspsr, dsp_run;
+	struct adau *adau = snd_soc_component_get_drvdata(component);
+	struct snd_soc_dapm_context *dapm = snd_soc_component_get_dapm(component);
+
+	snd_soc_dapm_mutex_lock(dapm);
 
 	ret = regmap_read(adau->regmap, ADAU17X1_DSP_SAMPLING_RATE, &dspsr);
 	if (ret)
-		return ret;
+		goto err;
+
+	ret = regmap_read(adau->regmap, ADAU17X1_DSP_RUN, &dsp_run);
+	if (ret)
+		goto err;
 
 	regmap_write(adau->regmap, ADAU17X1_DSP_ENABLE, 1);
 	regmap_write(adau->regmap, ADAU17X1_DSP_SAMPLING_RATE, 0xf);
+	regmap_write(adau->regmap, ADAU17X1_DSP_RUN, 0);
 
 	ret = sigmadsp_setup(adau->sigmadsp, rate);
 	if (ret) {
 		regmap_write(adau->regmap, ADAU17X1_DSP_ENABLE, 0);
-		return ret;
+		goto err;
 	}
 	regmap_write(adau->regmap, ADAU17X1_DSP_SAMPLING_RATE, dspsr);
+	regmap_write(adau->regmap, ADAU17X1_DSP_RUN, dsp_run);
 
-	return 0;
+err:
+	snd_soc_dapm_mutex_unlock(dapm);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(adau17x1_setup_firmware);
 
diff --git a/sound/soc/codecs/adau17x1.h b/sound/soc/codecs/adau17x1.h
index a7b1cb770814..e6fe87beec07 100644
--- a/sound/soc/codecs/adau17x1.h
+++ b/sound/soc/codecs/adau17x1.h
@@ -68,7 +68,8 @@ int adau17x1_resume(struct snd_soc_component *component);
 
 extern const struct snd_soc_dai_ops adau17x1_dai_ops;
 
-int adau17x1_setup_firmware(struct adau *adau, unsigned int rate);
+int adau17x1_setup_firmware(struct snd_soc_component *component,
+	unsigned int rate);
 bool adau17x1_has_dsp(struct adau *adau);
 
 #define ADAU17X1_CLOCK_CONTROL			0x4000
-- 
2.11.0