CoreSight July 2026

coresight@lists.linaro.org

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21 discussions

Re: [PATCH 1/2] coresight: Fix clock refcount imbalance on platform remove

by Yeoreum Yun

Reviewed-by: Yeoreum Yun <yeoreum.yun(a)arm.com> On Wed, Jul 01, 2026 at 02:05:02PM +0800, Jie Gan wrote: > coresight_get_enable_clocks() enables the programming clock and the > optional AT clock through devm_clk_get_optional_enabled(), which also > registers a devm action to call clk_disable_unprepare() when the driver > detaches. > > After probe, pm_runtime_put() allows the device to suspend and the > runtime suspend callback disables the same clocks. During remove the > device is left runtime suspended, so pm_runtime_disable() freezes it > with the clocks already disabled. The devm cleanup that runs afterwards > calls clk_disable_unprepare() a second time, underflowing the clock > enable refcount. > > Resume the device with pm_runtime_get_sync() before pm_runtime_disable() > so the clocks are enabled again and balance the devm-managed disable. > > This affects all CoreSight platform drivers that obtain their clocks > through coresight_get_enable_clocks(): catu, cpu-debug, ctcu, etm4x, > funnel, replicator, stm, tmc and tpiu. > > Fixes: 1abc1b212eff ("coresight: Appropriately disable programming clocks") > Signed-off-by: Jie Gan <jie.gan(a)oss.qualcomm.com> > --- > drivers/hwtracing/coresight/coresight-catu.c | 1 + > drivers/hwtracing/coresight/coresight-cpu-debug.c | 1 + > drivers/hwtracing/coresight/coresight-ctcu-core.c | 1 + > drivers/hwtracing/coresight/coresight-etm4x-core.c | 1 + > drivers/hwtracing/coresight/coresight-funnel.c | 1 + > drivers/hwtracing/coresight/coresight-replicator.c | 1 + > drivers/hwtracing/coresight/coresight-stm.c | 1 + > drivers/hwtracing/coresight/coresight-tmc-core.c | 1 + > drivers/hwtracing/coresight/coresight-tpiu.c | 1 + > 9 files changed, 9 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c > index ad8dafea7d2f..f7e501e6cbd7 100644 > --- a/drivers/hwtracing/coresight/coresight-catu.c > +++ b/drivers/hwtracing/coresight/coresight-catu.c > @@ -647,6 +647,7 @@ static void catu_platform_remove(struct platform_device *pdev) > return; > > __catu_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c > index 3a806c1d50ea..f7efae5b5ce5 100644 > --- a/drivers/hwtracing/coresight/coresight-cpu-debug.c > +++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c > @@ -711,6 +711,7 @@ static void debug_platform_remove(struct platform_device *pdev) > return; > > __debug_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-ctcu-core.c b/drivers/hwtracing/coresight/coresight-ctcu-core.c > index 9043cad42f01..9b6da29d9735 100644 > --- a/drivers/hwtracing/coresight/coresight-ctcu-core.c > +++ b/drivers/hwtracing/coresight/coresight-ctcu-core.c > @@ -266,6 +266,7 @@ static void ctcu_platform_remove(struct platform_device *pdev) > return; > > ctcu_remove(pdev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > index 14bb31bd6a0b..147761024c0f 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -2416,6 +2416,7 @@ static void etm4_remove_platform_dev(struct platform_device *pdev) > > if (drvdata) > etm4_remove_dev(drvdata); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c > index 0abc11f0690c..4c5b94640e6a 100644 > --- a/drivers/hwtracing/coresight/coresight-funnel.c > +++ b/drivers/hwtracing/coresight/coresight-funnel.c > @@ -334,6 +334,7 @@ static void funnel_platform_remove(struct platform_device *pdev) > return; > > funnel_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c > index 2f382de357ee..2d765f1f73b3 100644 > --- a/drivers/hwtracing/coresight/coresight-replicator.c > +++ b/drivers/hwtracing/coresight/coresight-replicator.c > @@ -313,6 +313,7 @@ static void replicator_platform_remove(struct platform_device *pdev) > return; > > replicator_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c > index 4e860519a73f..a653f1eebeca 100644 > --- a/drivers/hwtracing/coresight/coresight-stm.c > +++ b/drivers/hwtracing/coresight/coresight-stm.c > @@ -1026,6 +1026,7 @@ static void stm_platform_remove(struct platform_device *pdev) > return; > > __stm_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c > index bc5a133ada3e..c9cf486873e2 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -989,6 +989,7 @@ static void tmc_platform_remove(struct platform_device *pdev) > return; > > __tmc_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c > index 7b029d2eb389..72ac93749be1 100644 > --- a/drivers/hwtracing/coresight/coresight-tpiu.c > +++ b/drivers/hwtracing/coresight/coresight-tpiu.c > @@ -286,6 +286,7 @@ static void tpiu_platform_remove(struct platform_device *pdev) > return; > > __tpiu_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > > -- > 2.34.1 > -- Sincerely, Yeoreum Yun

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CoreSight July 2026