ASoC: msm8x16: fix the target crash due to dpm timeout

DPM timeout was happening due to the suspend call to the
codec driver being blocked.
This was due to a deadlock by acquiring the same mutex by the
suspend call and the work queue.
Fix by modifying the codeflow so that the deadlock is avoided.

CRs-Fixed: 681986
Change-Id: I96f11ee968a0e9bd267a80d2d11f1fa49985f5a9
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>

3 files changed, 47 insertions, 85 deletions

diff --git a/sound/soc/codecs/msm8x16-wcd.c b/sound/soc/codecs/msm8x16-wcd.c
index dda668bf5fdb..c88cc472e7b8 100644
--- a/sound/soc/codecs/msm8x16-wcd.c
+++ b/sound/soc/codecs/msm8x16-wcd.c
@@ -347,7 +347,7 @@ static int __msm8x16_wcd_reg_read(struct snd_soc_codec *codec,
 		ret = msm8x16_wcd_spmi_read(reg, 1, &temp);
 	else if (MSM8X16_WCD_IS_DIGITAL_REG(reg)) {
 		mutex_lock(&pdata->cdc_mclk_mutex);
-		if (atomic_read(&pdata->dis_work_mclk) == false) {
+		if (atomic_read(&pdata->mclk_enabled) == false) {
 			pdata->digital_cdc_clk.clk_val = pdata->mclk_freq;
 			ret = afe_set_digital_codec_core_clock(
 					AFE_PORT_ID_PRIMARY_MI2S_RX,
@@ -359,8 +359,8 @@ static int __msm8x16_wcd_reg_read(struct snd_soc_codec *codec,
 			pr_debug("%s: MCLK not enabled\n", __func__);
 			ret = msm8x16_wcd_ahb_read_device(
 					msm8x16_wcd, reg, 1, &temp);
-			atomic_set(&pdata->dis_work_mclk, true);
-			schedule_delayed_work(&pdata->enable_mclk_work, 50);
+			atomic_set(&pdata->mclk_enabled, true);
+			schedule_delayed_work(&pdata->disable_mclk_work, 50);
 err:
 			mutex_unlock(&pdata->cdc_mclk_mutex);
 			mutex_unlock(&msm8x16_wcd->io_lock);
@@ -397,7 +397,7 @@ static int __msm8x16_wcd_reg_write(struct snd_soc_codec *codec,
 		ret = msm8x16_wcd_spmi_write(reg, 1, &val);
 	else if (MSM8X16_WCD_IS_DIGITAL_REG(reg)) {
 		mutex_lock(&pdata->cdc_mclk_mutex);
-		if (atomic_read(&pdata->dis_work_mclk) == false) {
+		if (atomic_read(&pdata->mclk_enabled) == false) {
 			pr_debug("MCLK not enabled %s:\n", __func__);
 			pdata->digital_cdc_clk.clk_val = pdata->mclk_freq;
 			ret = afe_set_digital_codec_core_clock(
@@ -410,8 +410,8 @@ static int __msm8x16_wcd_reg_write(struct snd_soc_codec *codec,
 			}
 			ret = msm8x16_wcd_ahb_write_device(
 						msm8x16_wcd, reg, &val, 1);
-			atomic_set(&pdata->dis_work_mclk, true);
-			schedule_delayed_work(&pdata->enable_mclk_work, 50);
+			atomic_set(&pdata->mclk_enabled, true);
+			schedule_delayed_work(&pdata->disable_mclk_work, 50);
 err:
 			mutex_unlock(&pdata->cdc_mclk_mutex);
 			mutex_unlock(&msm8x16_wcd->io_lock);
@@ -3323,37 +3323,23 @@ int msm8x16_wcd_suspend(struct snd_soc_codec *codec)
 	struct msm8x16_wcd_pdata *msm8x16_pdata = msm8x16->dev->platform_data;
 
 	pdata = snd_soc_card_get_drvdata(codec->card);
-	pr_debug("%s: mclk cnt = %d, dis_work_mclk = %d"
-			"mclk_act = %d\n",
+	pr_debug("%s: mclk cnt = %d, mclk_enabled = %d\n",
 			__func__, atomic_read(&pdata->mclk_rsc_ref),
-			atomic_read(&pdata->dis_work_mclk),
-			atomic_read(&pdata->mclk_act));
-	mutex_lock(&pdata->cdc_mclk_mutex);
-	if ((atomic_read(&pdata->dis_work_mclk) == true) ||
-		(atomic_read(&pdata->mclk_rsc_ref) > 0)) {
-		pdata->digital_cdc_clk.clk_val = 0;
-		afe_set_digital_codec_core_clock(
+			atomic_read(&pdata->mclk_enabled));
+	if (atomic_read(&pdata->mclk_enabled) == true) {
+		cancel_delayed_work_sync(
+				&pdata->disable_mclk_work);
+		mutex_lock(&pdata->cdc_mclk_mutex);
+		if (atomic_read(&pdata->mclk_enabled) == true) {
+			pdata->digital_cdc_clk.clk_val = 0;
+			afe_set_digital_codec_core_clock(
 					AFE_PORT_ID_PRIMARY_MI2S_RX,
 					&pdata->digital_cdc_clk);
-		/*
-		 * set mclk activity to resource as
-		 * it will get updated accordingly going further in this
-		 * function.
-		 */
-		atomic_set(&pdata->mclk_act, MCLK_SUS_RSC);
-		if (atomic_read(&pdata->dis_work_mclk) == true) {
-			cancel_delayed_work_sync(
-					&pdata->enable_mclk_work);
-			atomic_set(&pdata->mclk_act, MCLK_SUS_DIS);
-			atomic_set(&pdata->dis_work_mclk, false);
+			atomic_set(&pdata->mclk_enabled, false);
 		}
-	} else
-		/*
-		 * mark no activity on mclk in this suspend
-		 */
-		atomic_set(&pdata->mclk_act, MCLK_SUS_NO_ACT);
+		mutex_unlock(&pdata->cdc_mclk_mutex);
+	}
 	msm8x16_wcd_disable_static_supplies_to_optimum(msm8x16, msm8x16_pdata);
-	mutex_unlock(&pdata->cdc_mclk_mutex);
 	return 0;
 }
 
@@ -3365,34 +3351,6 @@ int msm8x16_wcd_resume(struct snd_soc_codec *codec)
 
 	pdata = snd_soc_card_get_drvdata(codec->card);
 	msm8x16_wcd_enable_static_supplies_to_optimum(msm8x16, msm8x16_pdata);
-	pr_debug("%s: mclk cnt = %d, dis_work_mclk = %d"
-			"mclk_act = %d\n",
-			__func__, atomic_read(&pdata->mclk_rsc_ref),
-			atomic_read(&pdata->dis_work_mclk),
-			atomic_read(&pdata->mclk_act));
-	if (atomic_read(&pdata->mclk_act) == MCLK_SUS_NO_ACT)
-		/*
-		 * no activity in suspend just return
-		 */
-		return 0;
-	mutex_lock(&pdata->cdc_mclk_mutex);
-	if ((atomic_read(&pdata->dis_work_mclk) == false) ||
-		(atomic_read(&pdata->mclk_rsc_ref) > 0)) {
-		pdata->digital_cdc_clk.clk_val = pdata->mclk_freq;
-		afe_set_digital_codec_core_clock(
-					AFE_PORT_ID_PRIMARY_MI2S_RX,
-					&pdata->digital_cdc_clk);
-		if (atomic_read(&pdata->mclk_act) == MCLK_SUS_DIS) {
-			/*
-			 * MCLK activity marked as the disabled during suspend
-			 * this indicated MCLK was enabled to read and write the
-			 * AHB bus.
-			 */
-			atomic_set(&pdata->dis_work_mclk, true);
-			schedule_delayed_work(&pdata->enable_mclk_work, 50);
-		}
-	}
-	mutex_unlock(&pdata->cdc_mclk_mutex);
 	return 0;
 }
 
diff --git a/sound/soc/codecs/msm8x16-wcd.h b/sound/soc/codecs/msm8x16-wcd.h
index 7d497299264e..3cceb0a37fca 100644
--- a/sound/soc/codecs/msm8x16-wcd.h
+++ b/sound/soc/codecs/msm8x16-wcd.h
@@ -130,10 +130,9 @@ struct msm8916_asoc_mach_data {
 	int us_euro_gpio;
 	int mclk_freq;
 	atomic_t mclk_rsc_ref;
-	atomic_t dis_work_mclk;
-	atomic_t mclk_act;
+	atomic_t mclk_enabled;
 	struct mutex cdc_mclk_mutex;
-	struct delayed_work enable_mclk_work;
+	struct delayed_work disable_mclk_work;
 	struct afe_digital_clk_cfg digital_cdc_clk;
 };
 
diff --git a/sound/soc/msm/msm8x16.c b/sound/soc/msm/msm8x16.c
index a17cdfe1a6ef..18381a28d46e 100644
--- a/sound/soc/msm/msm8x16.c
+++ b/sound/soc/msm/msm8x16.c
@@ -593,28 +593,29 @@ static int msm8x16_enable_codec_ext_clk(struct snd_soc_codec *codec,
 		   atomic_read(&pdata->mclk_rsc_ref));
 	if (enable) {
 		if (atomic_inc_return(&pdata->mclk_rsc_ref) == 1) {
+			cancel_delayed_work_sync(
+					&pdata->disable_mclk_work);
 			mutex_lock(&pdata->cdc_mclk_mutex);
-			if (atomic_read(&pdata->dis_work_mclk) == true) {
-				cancel_delayed_work_sync(
-					&pdata->enable_mclk_work);
-			} else {
-				pdata->digital_cdc_clk.clk_val = pdata->mclk_freq;
+			if (atomic_read(&pdata->mclk_enabled) == false) {
+				pdata->digital_cdc_clk.clk_val =
+							pdata->mclk_freq;
 				afe_set_digital_codec_core_clock(
 						AFE_PORT_ID_PRIMARY_MI2S_RX,
 						&pdata->digital_cdc_clk);
-				atomic_set(&pdata->dis_work_mclk, true);
+				atomic_set(&pdata->mclk_enabled, true);
 			}
 			mutex_unlock(&pdata->cdc_mclk_mutex);
 		}
 	} else {
+		cancel_delayed_work_sync(&pdata->disable_mclk_work);
 		mutex_lock(&pdata->cdc_mclk_mutex);
-		atomic_set(&pdata->mclk_rsc_ref, 0);
-		cancel_delayed_work_sync(&pdata->enable_mclk_work);
-		pdata->digital_cdc_clk.clk_val = 0;
-		afe_set_digital_codec_core_clock(
-				AFE_PORT_ID_PRIMARY_MI2S_RX,
-				&pdata->digital_cdc_clk);
-		atomic_set(&pdata->dis_work_mclk, false);
+		if (atomic_read(&pdata->mclk_enabled) == true) {
+			pdata->digital_cdc_clk.clk_val = 0;
+			afe_set_digital_codec_core_clock(
+					AFE_PORT_ID_PRIMARY_MI2S_RX,
+					&pdata->digital_cdc_clk);
+			atomic_set(&pdata->mclk_enabled, false);
+		}
 		mutex_unlock(&pdata->cdc_mclk_mutex);
 	}
 	return ret;
@@ -1820,26 +1821,30 @@ static struct snd_soc_card bear_cards[MAX_SND_CARDS] = {
 	},
 };
 
-void enable_mclk(struct work_struct *work)
+void disable_mclk(struct work_struct *work)
 {
 	struct msm8916_asoc_mach_data *pdata = NULL;
 	struct delayed_work *dwork;
 	int ret = 0;
 
-	pr_debug("%s:\n", __func__);
 	dwork = to_delayed_work(work);
 	pdata = container_of(dwork, struct msm8916_asoc_mach_data,
-				enable_mclk_work);
+				disable_mclk_work);
 	mutex_lock(&pdata->cdc_mclk_mutex);
-	if (atomic_read(&pdata->dis_work_mclk) == true) {
-		pr_debug("clock enabled now disable\n");
+	pr_debug("%s: mclk_enabled %d mclk_rsc_ref %d\n", __func__,
+			atomic_read(&pdata->mclk_enabled),
+			atomic_read(&pdata->mclk_rsc_ref));
+
+	if (atomic_read(&pdata->mclk_enabled) == true
+		&& atomic_read(&pdata->mclk_rsc_ref) == 0) {
+		pr_debug("Disable the mclk\n");
 		pdata->digital_cdc_clk.clk_val = 0;
 		ret = afe_set_digital_codec_core_clock(
 				AFE_PORT_ID_PRIMARY_MI2S_RX,
 				&pdata->digital_cdc_clk);
 		if (ret < 0)
-			pr_err("failed to disable the MCLK\n");
-		atomic_set(&pdata->dis_work_mclk, false);
+			pr_err("%s failed to disable the MCLK\n", __func__);
+		atomic_set(&pdata->mclk_enabled, false);
 	}
 	mutex_unlock(&pdata->cdc_mclk_mutex);
 }
@@ -2171,10 +2176,10 @@ static int msm8x16_asoc_machine_probe(struct platform_device *pdev)
 	if (ret)
 		goto err;
 	/* initialize timer */
-	INIT_DELAYED_WORK(&pdata->enable_mclk_work, enable_mclk);
+	INIT_DELAYED_WORK(&pdata->disable_mclk_work, disable_mclk);
 	mutex_init(&pdata->cdc_mclk_mutex);
 	atomic_set(&pdata->mclk_rsc_ref, 0);
-	atomic_set(&pdata->dis_work_mclk, false);
+	atomic_set(&pdata->mclk_enabled, false);
 
 	ret = snd_soc_of_parse_audio_routing(card,
 			"qcom,audio-routing");