Re: [PATCH v3 5/9] coresight: Appropriately disable trace bus clocks

On 09/06/2025 17:00, 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") Reviewed-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Leo Yan leo.yan@arm.com

Can we consolidate the ATCLK handling to the core coresight helper for APB clocks ? It is an optional clock for all devices anyways ?

Cheers Suzuki

---

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 d5efb085b30d36b51ca591c1b595ef82481f5569..8e81b41eb22264f17606050fa8da277aae05c5cc 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 1c6204e1442211be6f3d7ca34bd2251ba796601b..baba2245b1dfb31f4bf19080e20c33df3a5b854f 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 36fc4e991458c112521c4261d73f3e58e9a3f995..b044a4125310ba4f8c88df295ec3684ab266682f 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);

@@ -261,10 +255,9 @@ 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); @@ -274,17 +267,10 @@ 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 6dd24eb10a94b0eb28f4f27afab845227e22b96c..9e8bd36e7a9a2fd061f41c56242ac2b11549daf5 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);

@@ -272,10 +266,8 @@ 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); @@ -286,17 +278,11 @@ 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 88ee453b2815444a550a2b932b28367eb93336b8..57fbe3ad0fb20501d4e7e5c478d1e56e98685c40 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 b2559c6fac6d2f02e0038e583cd324d7165c5aee..8d6179c83e5d3194d1f90e10c88fcc1faccf0cd7 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))