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[PATCH v1 6/9] coresight: Disable trace bus clock properly

Leo Yan posted 9 patches 8 months, 3 weeks ago
There is a newer version of this series
[PATCH v1 6/9] coresight: Disable trace bus clock properly
Posted by Leo Yan 8 months, 3 weeks ago 
Some CoreSight components have trace bus clocks 'atclk' and are enabled
using clk_prepare_enable().  These clocks are not disabled when modules
exit.

As atclk is optional, use devm_clk_get_optional_enabled() to manage it.
The benefit is the driver model layer can automatically disable and
release clocks.

Check the returned value with IS_ERR() to detect errors but leave the
NULL pointer case if the clock is not found.  And remove the error
handling codes which are no longer needed.

Fixes: d1839e687773 ("coresight: etm: retrieve and handle atclk")
Signed-off-by: Leo Yan <leo.yan@arm.com>
---
 drivers/hwtracing/coresight/coresight-etb10.c      | 10 ++++------
 drivers/hwtracing/coresight/coresight-etm3x-core.c |  9 +++------
 drivers/hwtracing/coresight/coresight-funnel.c     | 36 +++++++++++-------------------------
 drivers/hwtracing/coresight/coresight-replicator.c | 34 ++++++++++------------------------
 drivers/hwtracing/coresight/coresight-stm.c        |  9 +++------
 drivers/hwtracing/coresight/coresight-tpiu.c       | 10 +++-------
 6 files changed, 34 insertions(+), 74 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 7948597d483d..45c2f8f50a3f 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -730,12 +730,10 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
 	if (!drvdata)
 		return -ENOMEM;
 
-	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
-	if (!IS_ERR(drvdata->atclk)) {
-		ret = clk_prepare_enable(drvdata->atclk);
-		if (ret)
-			return ret;
-	}
+	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
+	if (IS_ERR(drvdata->atclk))
+		return PTR_ERR(drvdata->atclk);
+
 	dev_set_drvdata(dev, drvdata);
 
 	/* validity for the resource is already checked by the AMBA core */
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 8927bfaf3af2..adbb134f80e6 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -832,12 +832,9 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
 
 	spin_lock_init(&drvdata->spinlock);
 
-	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
-	if (!IS_ERR(drvdata->atclk)) {
-		ret = clk_prepare_enable(drvdata->atclk);
-		if (ret)
-			return ret;
-	}
+	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
+	if (IS_ERR(drvdata->atclk))
+		return PTR_ERR(drvdata->atclk);
 
 	drvdata->cpu = coresight_get_cpu(dev);
 	if (drvdata->cpu < 0)
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index 3fb9d0a37d55..ec6d3e656548 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -213,7 +213,6 @@ ATTRIBUTE_GROUPS(coresight_funnel);
 
 static int funnel_probe(struct device *dev, struct resource *res)
 {
-	int ret;
 	void __iomem *base;
 	struct coresight_platform_data *pdata = NULL;
 	struct funnel_drvdata *drvdata;
@@ -231,12 +230,9 @@ static int funnel_probe(struct device *dev, struct resource *res)
 	if (!drvdata)
 		return -ENOMEM;
 
-	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
-	if (!IS_ERR(drvdata->atclk)) {
-		ret = clk_prepare_enable(drvdata->atclk);
-		if (ret)
-			return ret;
-	}
+	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
+	if (IS_ERR(drvdata->atclk))
+		return PTR_ERR(drvdata->atclk);
 
 	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
 	if (IS_ERR(drvdata->pclk))
@@ -248,10 +244,8 @@ static int funnel_probe(struct device *dev, struct resource *res)
 	 */
 	if (res) {
 		base = devm_ioremap_resource(dev, res);
-		if (IS_ERR(base)) {
-			ret = PTR_ERR(base);
-			goto out_disable_clk;
-		}
+		if (IS_ERR(base))
+			return PTR_ERR(base);
 		drvdata->base = base;
 		desc.groups = coresight_funnel_groups;
 		desc.access = CSDEV_ACCESS_IOMEM(base);
@@ -260,10 +254,9 @@ static int funnel_probe(struct device *dev, struct resource *res)
 	dev_set_drvdata(dev, drvdata);
 
 	pdata = coresight_get_platform_data(dev);
-	if (IS_ERR(pdata)) {
-		ret = PTR_ERR(pdata);
-		goto out_disable_clk;
-	}
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+
 	dev->platform_data = pdata;
 
 	raw_spin_lock_init(&drvdata->spinlock);
@@ -273,17 +266,10 @@ static int funnel_probe(struct device *dev, struct resource *res)
 	desc.pdata = pdata;
 	desc.dev = dev;
 	drvdata->csdev = coresight_register(&desc);
-	if (IS_ERR(drvdata->csdev)) {
-		ret = PTR_ERR(drvdata->csdev);
-		goto out_disable_clk;
-	}
+	if (IS_ERR(drvdata->csdev))
+		return PTR_ERR(drvdata->csdev);
 
-	ret = 0;
-
-out_disable_clk:
-	if (ret && !IS_ERR_OR_NULL(drvdata->atclk))
-		clk_disable_unprepare(drvdata->atclk);
-	return ret;
+	return 0;
 }
 
 static int funnel_remove(struct device *dev)
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index 87346617b852..460af0f7b537 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -219,7 +219,6 @@ static const struct attribute_group *replicator_groups[] = {
 
 static int replicator_probe(struct device *dev, struct resource *res)
 {
-	int ret = 0;
 	struct coresight_platform_data *pdata = NULL;
 	struct replicator_drvdata *drvdata;
 	struct coresight_desc desc = { 0 };
@@ -238,12 +237,9 @@ static int replicator_probe(struct device *dev, struct resource *res)
 	if (!drvdata)
 		return -ENOMEM;
 
-	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
-	if (!IS_ERR(drvdata->atclk)) {
-		ret = clk_prepare_enable(drvdata->atclk);
-		if (ret)
-			return ret;
-	}
+	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
+	if (IS_ERR(drvdata->atclk))
+		return PTR_ERR(drvdata->atclk);
 
 	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
 	if (IS_ERR(drvdata->pclk))
@@ -255,10 +251,8 @@ static int replicator_probe(struct device *dev, struct resource *res)
 	 */
 	if (res) {
 		base = devm_ioremap_resource(dev, res);
-		if (IS_ERR(base)) {
-			ret = PTR_ERR(base);
-			goto out_disable_clk;
-		}
+		if (IS_ERR(base))
+			return PTR_ERR(base);
 		drvdata->base = base;
 		desc.groups = replicator_groups;
 		desc.access = CSDEV_ACCESS_IOMEM(base);
@@ -271,10 +265,8 @@ static int replicator_probe(struct device *dev, struct resource *res)
 	dev_set_drvdata(dev, drvdata);
 
 	pdata = coresight_get_platform_data(dev);
-	if (IS_ERR(pdata)) {
-		ret = PTR_ERR(pdata);
-		goto out_disable_clk;
-	}
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
 	dev->platform_data = pdata;
 
 	raw_spin_lock_init(&drvdata->spinlock);
@@ -285,17 +277,11 @@ static int replicator_probe(struct device *dev, struct resource *res)
 	desc.dev = dev;
 
 	drvdata->csdev = coresight_register(&desc);
-	if (IS_ERR(drvdata->csdev)) {
-		ret = PTR_ERR(drvdata->csdev);
-		goto out_disable_clk;
-	}
+	if (IS_ERR(drvdata->csdev))
+		return PTR_ERR(drvdata->csdev);
 
 	replicator_reset(drvdata);
-
-out_disable_clk:
-	if (ret && !IS_ERR_OR_NULL(drvdata->atclk))
-		clk_disable_unprepare(drvdata->atclk);
-	return ret;
+	return 0;
 }
 
 static int replicator_remove(struct device *dev)
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index c32d0bd92f30..f13fbab4d7a2 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -842,12 +842,9 @@ static int __stm_probe(struct device *dev, struct resource *res)
 	if (!drvdata)
 		return -ENOMEM;
 
-	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
-	if (!IS_ERR(drvdata->atclk)) {
-		ret = clk_prepare_enable(drvdata->atclk);
-		if (ret)
-			return ret;
-	}
+	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
+	if (IS_ERR(drvdata->atclk))
+		return PTR_ERR(drvdata->atclk);
 
 	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
 	if (IS_ERR(drvdata->pclk))
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index 4b9634941752..cac1b5bba086 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -128,7 +128,6 @@ static const struct coresight_ops tpiu_cs_ops = {
 
 static int __tpiu_probe(struct device *dev, struct resource *res)
 {
-	int ret;
 	void __iomem *base;
 	struct coresight_platform_data *pdata = NULL;
 	struct tpiu_drvdata *drvdata;
@@ -144,12 +143,9 @@ static int __tpiu_probe(struct device *dev, struct resource *res)
 
 	spin_lock_init(&drvdata->spinlock);
 
-	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
-	if (!IS_ERR(drvdata->atclk)) {
-		ret = clk_prepare_enable(drvdata->atclk);
-		if (ret)
-			return ret;
-	}
+	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
+	if (IS_ERR(drvdata->atclk))
+		return PTR_ERR(drvdata->atclk);
 
 	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
 	if (IS_ERR(drvdata->pclk))
-- 
2.34.1
Re: [PATCH v1 6/9] coresight: Disable trace bus clock properly
Posted by Anshuman Khandual 8 months, 2 weeks ago 

On 3/27/25 17:08, Leo Yan wrote:
> Some CoreSight components have trace bus clocks 'atclk' and are enabled
> using clk_prepare_enable().  These clocks are not disabled when modules
> exit.
> 
> As atclk is optional, use devm_clk_get_optional_enabled() to manage it.
> The benefit is the driver model layer can automatically disable and
> release clocks.
> 
> Check the returned value with IS_ERR() to detect errors but leave the
> NULL pointer case if the clock is not found.  And remove the error
> handling codes which are no longer needed.
> 
> Fixes: d1839e687773 ("coresight: etm: retrieve and handle atclk")
> Signed-off-by: Leo Yan <leo.yan@arm.com>

This patch probably should be positioned right after [PATCH 4/9] which
replaces pclk clock init with devm_clk_get_enabled().

> ---
>  drivers/hwtracing/coresight/coresight-etb10.c      | 10 ++++------
>  drivers/hwtracing/coresight/coresight-etm3x-core.c |  9 +++------
>  drivers/hwtracing/coresight/coresight-funnel.c     | 36 +++++++++++-------------------------
>  drivers/hwtracing/coresight/coresight-replicator.c | 34 ++++++++++------------------------
>  drivers/hwtracing/coresight/coresight-stm.c        |  9 +++------
>  drivers/hwtracing/coresight/coresight-tpiu.c       | 10 +++-------
>  6 files changed, 34 insertions(+), 74 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
> index 7948597d483d..45c2f8f50a3f 100644
> --- a/drivers/hwtracing/coresight/coresight-etb10.c
> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
> @@ -730,12 +730,10 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
>  	if (!drvdata)
>  		return -ENOMEM;
>  
> -	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
> -	if (!IS_ERR(drvdata->atclk)) {
> -		ret = clk_prepare_enable(drvdata->atclk);
> -		if (ret)
> -			return ret;
> -	}
> +	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
> +	if (IS_ERR(drvdata->atclk))
> +		return PTR_ERR(drvdata->atclk);
> +
>  	dev_set_drvdata(dev, drvdata);
>  
>  	/* validity for the resource is already checked by the AMBA core */
> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> index 8927bfaf3af2..adbb134f80e6 100644
> --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> @@ -832,12 +832,9 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
>  
>  	spin_lock_init(&drvdata->spinlock);
>  
> -	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
> -	if (!IS_ERR(drvdata->atclk)) {
> -		ret = clk_prepare_enable(drvdata->atclk);
> -		if (ret)
> -			return ret;
> -	}
> +	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
> +	if (IS_ERR(drvdata->atclk))
> +		return PTR_ERR(drvdata->atclk);
>  
>  	drvdata->cpu = coresight_get_cpu(dev);
>  	if (drvdata->cpu < 0)
> diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
> index 3fb9d0a37d55..ec6d3e656548 100644
> --- a/drivers/hwtracing/coresight/coresight-funnel.c
> +++ b/drivers/hwtracing/coresight/coresight-funnel.c
> @@ -213,7 +213,6 @@ ATTRIBUTE_GROUPS(coresight_funnel);
>  
>  static int funnel_probe(struct device *dev, struct resource *res)
>  {
> -	int ret;
>  	void __iomem *base;
>  	struct coresight_platform_data *pdata = NULL;
>  	struct funnel_drvdata *drvdata;
> @@ -231,12 +230,9 @@ static int funnel_probe(struct device *dev, struct resource *res)
>  	if (!drvdata)
>  		return -ENOMEM;
>  
> -	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
> -	if (!IS_ERR(drvdata->atclk)) {
> -		ret = clk_prepare_enable(drvdata->atclk);
> -		if (ret)
> -			return ret;
> -	}
> +	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
> +	if (IS_ERR(drvdata->atclk))
> +		return PTR_ERR(drvdata->atclk);
>  
>  	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
>  	if (IS_ERR(drvdata->pclk))
> @@ -248,10 +244,8 @@ static int funnel_probe(struct device *dev, struct resource *res)
>  	 */
>  	if (res) {
>  		base = devm_ioremap_resource(dev, res);
> -		if (IS_ERR(base)) {
> -			ret = PTR_ERR(base);
> -			goto out_disable_clk;
> -		}
> +		if (IS_ERR(base))
> +			return PTR_ERR(base);
>  		drvdata->base = base;
>  		desc.groups = coresight_funnel_groups;
>  		desc.access = CSDEV_ACCESS_IOMEM(base);
> @@ -260,10 +254,9 @@ static int funnel_probe(struct device *dev, struct resource *res)
>  	dev_set_drvdata(dev, drvdata);
>  
>  	pdata = coresight_get_platform_data(dev);
> -	if (IS_ERR(pdata)) {
> -		ret = PTR_ERR(pdata);
> -		goto out_disable_clk;
> -	}
> +	if (IS_ERR(pdata))
> +		return PTR_ERR(pdata);
> +
>  	dev->platform_data = pdata;
>  
>  	raw_spin_lock_init(&drvdata->spinlock);
> @@ -273,17 +266,10 @@ static int funnel_probe(struct device *dev, struct resource *res)
>  	desc.pdata = pdata;
>  	desc.dev = dev;
>  	drvdata->csdev = coresight_register(&desc);
> -	if (IS_ERR(drvdata->csdev)) {
> -		ret = PTR_ERR(drvdata->csdev);
> -		goto out_disable_clk;
> -	}
> +	if (IS_ERR(drvdata->csdev))
> +		return PTR_ERR(drvdata->csdev);
>  
> -	ret = 0;
> -
> -out_disable_clk:
> -	if (ret && !IS_ERR_OR_NULL(drvdata->atclk))
> -		clk_disable_unprepare(drvdata->atclk);
> -	return ret;
> +	return 0;
>  }
>  
>  static int funnel_remove(struct device *dev)
> diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
> index 87346617b852..460af0f7b537 100644
> --- a/drivers/hwtracing/coresight/coresight-replicator.c
> +++ b/drivers/hwtracing/coresight/coresight-replicator.c
> @@ -219,7 +219,6 @@ static const struct attribute_group *replicator_groups[] = {
>  
>  static int replicator_probe(struct device *dev, struct resource *res)
>  {
> -	int ret = 0;
>  	struct coresight_platform_data *pdata = NULL;
>  	struct replicator_drvdata *drvdata;
>  	struct coresight_desc desc = { 0 };
> @@ -238,12 +237,9 @@ static int replicator_probe(struct device *dev, struct resource *res)
>  	if (!drvdata)
>  		return -ENOMEM;
>  
> -	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
> -	if (!IS_ERR(drvdata->atclk)) {
> -		ret = clk_prepare_enable(drvdata->atclk);
> -		if (ret)
> -			return ret;
> -	}
> +	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
> +	if (IS_ERR(drvdata->atclk))
> +		return PTR_ERR(drvdata->atclk);
>  
>  	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
>  	if (IS_ERR(drvdata->pclk))
> @@ -255,10 +251,8 @@ static int replicator_probe(struct device *dev, struct resource *res)
>  	 */
>  	if (res) {
>  		base = devm_ioremap_resource(dev, res);
> -		if (IS_ERR(base)) {
> -			ret = PTR_ERR(base);
> -			goto out_disable_clk;
> -		}
> +		if (IS_ERR(base))
> +			return PTR_ERR(base);
>  		drvdata->base = base;
>  		desc.groups = replicator_groups;
>  		desc.access = CSDEV_ACCESS_IOMEM(base);
> @@ -271,10 +265,8 @@ static int replicator_probe(struct device *dev, struct resource *res)
>  	dev_set_drvdata(dev, drvdata);
>  
>  	pdata = coresight_get_platform_data(dev);
> -	if (IS_ERR(pdata)) {
> -		ret = PTR_ERR(pdata);
> -		goto out_disable_clk;
> -	}
> +	if (IS_ERR(pdata))
> +		return PTR_ERR(pdata);
>  	dev->platform_data = pdata;
>  
>  	raw_spin_lock_init(&drvdata->spinlock);
> @@ -285,17 +277,11 @@ static int replicator_probe(struct device *dev, struct resource *res)
>  	desc.dev = dev;
>  
>  	drvdata->csdev = coresight_register(&desc);
> -	if (IS_ERR(drvdata->csdev)) {
> -		ret = PTR_ERR(drvdata->csdev);
> -		goto out_disable_clk;
> -	}
> +	if (IS_ERR(drvdata->csdev))
> +		return PTR_ERR(drvdata->csdev);
>  
>  	replicator_reset(drvdata);
> -
> -out_disable_clk:
> -	if (ret && !IS_ERR_OR_NULL(drvdata->atclk))
> -		clk_disable_unprepare(drvdata->atclk);
> -	return ret;
> +	return 0;
>  }
>  
>  static int replicator_remove(struct device *dev)
> diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
> index c32d0bd92f30..f13fbab4d7a2 100644
> --- a/drivers/hwtracing/coresight/coresight-stm.c
> +++ b/drivers/hwtracing/coresight/coresight-stm.c
> @@ -842,12 +842,9 @@ static int __stm_probe(struct device *dev, struct resource *res)
>  	if (!drvdata)
>  		return -ENOMEM;
>  
> -	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
> -	if (!IS_ERR(drvdata->atclk)) {
> -		ret = clk_prepare_enable(drvdata->atclk);
> -		if (ret)
> -			return ret;
> -	}
> +	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
> +	if (IS_ERR(drvdata->atclk))
> +		return PTR_ERR(drvdata->atclk);
>  
>  	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
>  	if (IS_ERR(drvdata->pclk))
> diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
> index 4b9634941752..cac1b5bba086 100644
> --- a/drivers/hwtracing/coresight/coresight-tpiu.c
> +++ b/drivers/hwtracing/coresight/coresight-tpiu.c
> @@ -128,7 +128,6 @@ static const struct coresight_ops tpiu_cs_ops = {
>  
>  static int __tpiu_probe(struct device *dev, struct resource *res)
>  {
> -	int ret;
>  	void __iomem *base;
>  	struct coresight_platform_data *pdata = NULL;
>  	struct tpiu_drvdata *drvdata;
> @@ -144,12 +143,9 @@ static int __tpiu_probe(struct device *dev, struct resource *res)
>  
>  	spin_lock_init(&drvdata->spinlock);
>  
> -	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
> -	if (!IS_ERR(drvdata->atclk)) {
> -		ret = clk_prepare_enable(drvdata->atclk);
> -		if (ret)
> -			return ret;
> -	}
> +	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
> +	if (IS_ERR(drvdata->atclk))
> +		return PTR_ERR(drvdata->atclk);
>  
>  	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
>  	if (IS_ERR(drvdata->pclk))
Re: [PATCH v1 6/9] coresight: Disable trace bus clock properly
Posted by Leo Yan 7 months, 4 weeks ago 
On Thu, Apr 03, 2025 at 12:55:46PM +0530, Anshuman Khandual wrote:
> 
> On 3/27/25 17:08, Leo Yan wrote:
> > Some CoreSight components have trace bus clocks 'atclk' and are enabled
> > using clk_prepare_enable().  These clocks are not disabled when modules
> > exit.
> > 
> > As atclk is optional, use devm_clk_get_optional_enabled() to manage it.
> > The benefit is the driver model layer can automatically disable and
> > release clocks.
> > 
> > Check the returned value with IS_ERR() to detect errors but leave the
> > NULL pointer case if the clock is not found.  And remove the error
> > handling codes which are no longer needed.
> > 
> > Fixes: d1839e687773 ("coresight: etm: retrieve and handle atclk")
> > Signed-off-by: Leo Yan <leo.yan@arm.com>
> 
> This patch probably should be positioned right after [PATCH 4/9] which
> replaces pclk clock init with devm_clk_get_enabled().

Sure.  Will reorder patches for this.

Thanks,
Leo

Patchew 2.1-devel-b67e4c2

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