* [PATCH] coresight: handle runtime PM resume failures
@ 2026-09-11 10:28 Yuanfang Zhang
2026-09-11 13:11 ` Ulf Hansson
2026-09-16 10:30 ` Leo Yan
0 siblings, 2 replies; 3+ messages in thread
From: Yuanfang Zhang @ 2026-09-11 10:28 UTC (permalink / raw)
To: Suzuki K Poulose, Mike Leach, James Clark, Leo Yan,
Alexander Shishkin, Maxime Coquelin, Alexandre Torgue
Cc: kernel, coresight, linux-arm-kernel, linux-kernel, linux-stm32,
Yuanfang Zhang
When a CoreSight component's parent power domain, such as a CPU cluster
genpd, fails to power on, runtime resume returns a negative error. Several
call sites ignored that error and continued to access registers on an
unpowered device, risking an external abort.
Replace the remaining pm_runtime_get_sync() calls with
pm_runtime_resume_and_get(), which restores the runtime PM usage count
when resume fails. Abort before accessing hardware and propagate the
error to the caller.
In coresight_get_ref(), unwind the module and device references. In
debug_enable_func(), roll back the CPUs that resumed successfully before
the failure. Finally, release the mode acquired by stm_enable() if its
runtime resume fails.
Signed-off-by: Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>
---
This patch converts the remaining CoreSight pm_runtime_get_sync() users
to pm_runtime_resume_and_get(), propagates resume failures before
hardware access, and completes the related module, device, CPU and mode
unwind paths.
---
drivers/hwtracing/coresight/coresight-core.c | 13 ++++++++++---
drivers/hwtracing/coresight/coresight-cpu-debug.c | 10 +++++-----
drivers/hwtracing/coresight/coresight-cti-sysfs.c | 10 ++++++++--
drivers/hwtracing/coresight/coresight-etm3x-sysfs.c | 10 ++++++++--
drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 5 ++++-
drivers/hwtracing/coresight/coresight-funnel.c | 5 ++++-
drivers/hwtracing/coresight/coresight-stm.c | 7 ++++++-
drivers/hwtracing/coresight/coresight-sysfs.c | 11 +++++++++--
8 files changed, 54 insertions(+), 17 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 928488a216d4eafa3cdb5f882ae5f44ddaff0448..ff93a017dbe22b01236ac2e5021da9b82890e72c 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -822,14 +822,16 @@ struct coresight_device *coresight_get_sink_by_id(u32 id)
*
* @csdev: The coresight device to get a reference on.
*
- * Return true in successful case and power up the device.
- * Return false when failed to get reference of module.
+ * Return true on success and power up the device.
+ * Return false if a reference cannot be obtained or the device cannot be
+ * powered up.
*/
static bool coresight_get_ref(struct coresight_device *csdev)
{
struct device *dev = &csdev->dev;
struct device *parent = csdev->dev.parent;
struct device_driver *drv;
+ int ret;
/* Make sure csdev can't go away */
get_device(dev);
@@ -843,9 +845,14 @@ static bool coresight_get_ref(struct coresight_device *csdev)
goto err_module;
/* Make sure the device is powered on */
- pm_runtime_get_sync(parent);
+ ret = pm_runtime_resume_and_get(parent);
+ if (ret < 0)
+ goto err_pm;
+
return true;
+err_pm:
+ module_put(drv->owner);
err_module:
put_device(parent);
put_device(dev);
diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c
index 3a806c1d50eafb4249ab516ef846e437831b9681..39602d610e5b22ec4f165dbb126a7c06aea08eb0 100644
--- a/drivers/hwtracing/coresight/coresight-cpu-debug.c
+++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c
@@ -429,19 +429,19 @@ static int debug_enable_func(void)
if (!drvdata)
continue;
- ret = pm_runtime_get_sync(drvdata->dev);
+ ret = pm_runtime_resume_and_get(drvdata->dev);
if (ret < 0)
goto err;
- else
- cpumask_set_cpu(cpu, &mask);
+
+ cpumask_set_cpu(cpu, &mask);
}
return 0;
err:
/*
- * If pm_runtime_get_sync() has failed, need rollback on
- * all the other CPUs that have been enabled before that.
+ * If runtime resume has failed, roll back all the other CPUs
+ * that have been enabled before that.
*/
for_each_cpu(cpu, &mask) {
drvdata = per_cpu(debug_drvdata, cpu);
diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
index 3fe2c916d228808233ef19e9213a0cc0ce3cf297..6886b8713368058b9cf33ab7fafb5f87e23c1ec9 100644
--- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
@@ -167,8 +167,11 @@ static ssize_t coresight_cti_reg_show(struct device *dev,
struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
struct cs_off_attribute *cti_attr = container_of(attr, struct cs_off_attribute, attr);
u32 val = 0;
+ int ret;
- pm_runtime_get_sync(dev->parent);
+ ret = pm_runtime_resume_and_get(dev->parent);
+ if (ret < 0)
+ return ret;
scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
val = cti_read_single_reg(drvdata, cti_attr->off);
@@ -185,11 +188,14 @@ static __maybe_unused ssize_t coresight_cti_reg_store(struct device *dev,
struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
struct cs_off_attribute *cti_attr = container_of(attr, struct cs_off_attribute, attr);
unsigned long val = 0;
+ int ret;
if (kstrtoul(buf, 0, &val))
return -EINVAL;
- pm_runtime_get_sync(dev->parent);
+ ret = pm_runtime_resume_and_get(dev->parent);
+ if (ret < 0)
+ return ret;
scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
cti_write_single_reg(drvdata, cti_attr->off, val);
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
index b3c67e96a82a4995515457d1ac0a5b183b162f0f..b34e282ec4a5f37f7de1d2ff118042b47368acd7 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
@@ -47,8 +47,11 @@ static ssize_t etmsr_show(struct device *dev,
{
unsigned long flags, val;
struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ int ret;
- pm_runtime_get_sync(dev->parent);
+ ret = pm_runtime_resume_and_get(dev->parent);
+ if (ret < 0)
+ return ret;
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->csa.base);
@@ -933,13 +936,16 @@ static ssize_t seq_curr_state_show(struct device *dev,
unsigned long val, flags;
struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
struct etm_config *config = &drvdata->config;
+ int ret;
if (!coresight_get_mode(drvdata->csdev)) {
val = config->seq_curr_state;
goto out;
}
- pm_runtime_get_sync(dev->parent);
+ ret = pm_runtime_resume_and_get(dev->parent);
+ if (ret < 0)
+ return ret;
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->csa.base);
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index cc6cdd3ae29d502a2e67f07400de957b6dc71af6..55e05c20b302d4bf55c4df30c9ee6d6a1b5f1031 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -2457,10 +2457,13 @@ static ssize_t coresight_etm4x_reg_show(struct device *dev,
{
u32 val, offset;
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ int ret;
offset = coresight_etm4x_attr_to_offset(d_attr);
- pm_runtime_get_sync(dev->parent);
+ ret = pm_runtime_resume_and_get(dev->parent);
+ if (ret < 0)
+ return ret;
val = etmv4_cross_read(drvdata, offset);
pm_runtime_put_sync(dev->parent);
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index 0abc11f0690c5272ebd55df9e98544e3b401cfe6..5824a1e4d046a3caf5b32ed1d8526b8bd7e9ca76 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -190,9 +190,12 @@ static ssize_t funnel_ctrl_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
u32 val;
+ int ret;
struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
- pm_runtime_get_sync(dev->parent);
+ ret = pm_runtime_resume_and_get(dev->parent);
+ if (ret < 0)
+ return ret;
val = get_funnel_ctrl_hw(drvdata);
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index 4e860519a73f6fff640090cf58298b89a31e6359..b9f15990ed994ea827c8e237d764e74d8d231ddd 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -196,6 +196,7 @@ static int stm_enable(struct coresight_device *csdev, struct perf_event *event,
__maybe_unused struct coresight_path *path)
{
struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ int ret;
if (mode != CS_MODE_SYSFS)
return -EINVAL;
@@ -205,7 +206,11 @@ static int stm_enable(struct coresight_device *csdev, struct perf_event *event,
return -EBUSY;
}
- pm_runtime_get_sync(csdev->dev.parent);
+ ret = pm_runtime_resume_and_get(csdev->dev.parent);
+ if (ret < 0) {
+ coresight_set_mode(csdev, CS_MODE_DISABLED);
+ return ret;
+ }
spin_lock(&drvdata->spinlock);
stm_enable_hw(drvdata);
diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
index 4b010f8bc4c08da31b3d295be6c37b6d941629d2..5849dfbd9d0bd3ad10734919f78bc39cc968539c 100644
--- a/drivers/hwtracing/coresight/coresight-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -17,8 +17,12 @@ ssize_t coresight_simple_show_pair(struct device *_dev,
struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
struct cs_pair_attribute *cs_attr = container_of(attr, struct cs_pair_attribute, attr);
u64 val;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(_dev->parent);
+ if (ret < 0)
+ return ret;
- pm_runtime_get_sync(_dev->parent);
val = csdev_access_relaxed_read_pair(&csdev->access, cs_attr->lo_off, cs_attr->hi_off);
pm_runtime_put_sync(_dev->parent);
return sysfs_emit(buf, "0x%llx\n", val);
@@ -31,8 +35,11 @@ ssize_t coresight_simple_show32(struct device *_dev,
struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
struct cs_off_attribute *cs_attr = container_of(attr, struct cs_off_attribute, attr);
u64 val;
+ int ret;
- pm_runtime_get_sync(_dev->parent);
+ ret = pm_runtime_resume_and_get(_dev->parent);
+ if (ret < 0)
+ return ret;
val = csdev_access_relaxed_read32(&csdev->access, cs_attr->off);
pm_runtime_put_sync(_dev->parent);
return sysfs_emit(buf, "0x%llx\n", val);
---
base-commit: 08df884136f1c1197bab2a27814404fd329d9aac
change-id: 20260911-b4-coresight-runtime-pm-failures-70f250927aeb
Best regards,
--
Yuanfang Zhang <yuanfang@qti.qualcomm.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] coresight: handle runtime PM resume failures
2026-09-11 10:28 [PATCH] coresight: handle runtime PM resume failures Yuanfang Zhang
@ 2026-09-11 13:11 ` Ulf Hansson
2026-09-16 10:30 ` Leo Yan
1 sibling, 0 replies; 3+ messages in thread
From: Ulf Hansson @ 2026-09-11 13:11 UTC (permalink / raw)
To: Yuanfang Zhang
Cc: Suzuki K Poulose, Mike Leach, James Clark, Leo Yan,
Alexander Shishkin, Maxime Coquelin, Alexandre Torgue, kernel,
coresight, linux-arm-kernel, linux-kernel, linux-stm32
On Fri, Sep 11, 2026 at 12:29 PM Yuanfang Zhang
<yuanfang.zhang@oss.qualcomm.com> wrote:
>
> When a CoreSight component's parent power domain, such as a CPU cluster
> genpd, fails to power on, runtime resume returns a negative error. Several
> call sites ignored that error and continued to access registers on an
> unpowered device, risking an external abort.
>
> Replace the remaining pm_runtime_get_sync() calls with
> pm_runtime_resume_and_get(), which restores the runtime PM usage count
> when resume fails. Abort before accessing hardware and propagate the
> error to the caller.
>
> In coresight_get_ref(), unwind the module and device references. In
> debug_enable_func(), roll back the CPUs that resumed successfully before
> the failure. Finally, release the mode acquired by stm_enable() if its
> runtime resume fails.
>
> Signed-off-by: Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>
Feel free to add:
Reviewed-by: Ulf Hansson <ulfh@kernel.org>
Kind regards
Uffe
> ---
> This patch converts the remaining CoreSight pm_runtime_get_sync() users
> to pm_runtime_resume_and_get(), propagates resume failures before
> hardware access, and completes the related module, device, CPU and mode
> unwind paths.
> ---
> drivers/hwtracing/coresight/coresight-core.c | 13 ++++++++++---
> drivers/hwtracing/coresight/coresight-cpu-debug.c | 10 +++++-----
> drivers/hwtracing/coresight/coresight-cti-sysfs.c | 10 ++++++++--
> drivers/hwtracing/coresight/coresight-etm3x-sysfs.c | 10 ++++++++--
> drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 5 ++++-
> drivers/hwtracing/coresight/coresight-funnel.c | 5 ++++-
> drivers/hwtracing/coresight/coresight-stm.c | 7 ++++++-
> drivers/hwtracing/coresight/coresight-sysfs.c | 11 +++++++++--
> 8 files changed, 54 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 928488a216d4eafa3cdb5f882ae5f44ddaff0448..ff93a017dbe22b01236ac2e5021da9b82890e72c 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -822,14 +822,16 @@ struct coresight_device *coresight_get_sink_by_id(u32 id)
> *
> * @csdev: The coresight device to get a reference on.
> *
> - * Return true in successful case and power up the device.
> - * Return false when failed to get reference of module.
> + * Return true on success and power up the device.
> + * Return false if a reference cannot be obtained or the device cannot be
> + * powered up.
> */
> static bool coresight_get_ref(struct coresight_device *csdev)
> {
> struct device *dev = &csdev->dev;
> struct device *parent = csdev->dev.parent;
> struct device_driver *drv;
> + int ret;
>
> /* Make sure csdev can't go away */
> get_device(dev);
> @@ -843,9 +845,14 @@ static bool coresight_get_ref(struct coresight_device *csdev)
> goto err_module;
>
> /* Make sure the device is powered on */
> - pm_runtime_get_sync(parent);
> + ret = pm_runtime_resume_and_get(parent);
> + if (ret < 0)
> + goto err_pm;
> +
> return true;
>
> +err_pm:
> + module_put(drv->owner);
> err_module:
> put_device(parent);
> put_device(dev);
> diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c
> index 3a806c1d50eafb4249ab516ef846e437831b9681..39602d610e5b22ec4f165dbb126a7c06aea08eb0 100644
> --- a/drivers/hwtracing/coresight/coresight-cpu-debug.c
> +++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c
> @@ -429,19 +429,19 @@ static int debug_enable_func(void)
> if (!drvdata)
> continue;
>
> - ret = pm_runtime_get_sync(drvdata->dev);
> + ret = pm_runtime_resume_and_get(drvdata->dev);
> if (ret < 0)
> goto err;
> - else
> - cpumask_set_cpu(cpu, &mask);
> +
> + cpumask_set_cpu(cpu, &mask);
> }
>
> return 0;
>
> err:
> /*
> - * If pm_runtime_get_sync() has failed, need rollback on
> - * all the other CPUs that have been enabled before that.
> + * If runtime resume has failed, roll back all the other CPUs
> + * that have been enabled before that.
> */
> for_each_cpu(cpu, &mask) {
> drvdata = per_cpu(debug_drvdata, cpu);
> diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> index 3fe2c916d228808233ef19e9213a0cc0ce3cf297..6886b8713368058b9cf33ab7fafb5f87e23c1ec9 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> @@ -167,8 +167,11 @@ static ssize_t coresight_cti_reg_show(struct device *dev,
> struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
> struct cs_off_attribute *cti_attr = container_of(attr, struct cs_off_attribute, attr);
> u32 val = 0;
> + int ret;
>
> - pm_runtime_get_sync(dev->parent);
> + ret = pm_runtime_resume_and_get(dev->parent);
> + if (ret < 0)
> + return ret;
>
> scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
> val = cti_read_single_reg(drvdata, cti_attr->off);
> @@ -185,11 +188,14 @@ static __maybe_unused ssize_t coresight_cti_reg_store(struct device *dev,
> struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
> struct cs_off_attribute *cti_attr = container_of(attr, struct cs_off_attribute, attr);
> unsigned long val = 0;
> + int ret;
>
> if (kstrtoul(buf, 0, &val))
> return -EINVAL;
>
> - pm_runtime_get_sync(dev->parent);
> + ret = pm_runtime_resume_and_get(dev->parent);
> + if (ret < 0)
> + return ret;
>
> scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
> cti_write_single_reg(drvdata, cti_attr->off, val);
> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
> index b3c67e96a82a4995515457d1ac0a5b183b162f0f..b34e282ec4a5f37f7de1d2ff118042b47368acd7 100644
> --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
> @@ -47,8 +47,11 @@ static ssize_t etmsr_show(struct device *dev,
> {
> unsigned long flags, val;
> struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> + int ret;
>
> - pm_runtime_get_sync(dev->parent);
> + ret = pm_runtime_resume_and_get(dev->parent);
> + if (ret < 0)
> + return ret;
> spin_lock_irqsave(&drvdata->spinlock, flags);
> CS_UNLOCK(drvdata->csa.base);
>
> @@ -933,13 +936,16 @@ static ssize_t seq_curr_state_show(struct device *dev,
> unsigned long val, flags;
> struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> struct etm_config *config = &drvdata->config;
> + int ret;
>
> if (!coresight_get_mode(drvdata->csdev)) {
> val = config->seq_curr_state;
> goto out;
> }
>
> - pm_runtime_get_sync(dev->parent);
> + ret = pm_runtime_resume_and_get(dev->parent);
> + if (ret < 0)
> + return ret;
> spin_lock_irqsave(&drvdata->spinlock, flags);
>
> CS_UNLOCK(drvdata->csa.base);
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> index cc6cdd3ae29d502a2e67f07400de957b6dc71af6..55e05c20b302d4bf55c4df30c9ee6d6a1b5f1031 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> @@ -2457,10 +2457,13 @@ static ssize_t coresight_etm4x_reg_show(struct device *dev,
> {
> u32 val, offset;
> struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
> + int ret;
>
> offset = coresight_etm4x_attr_to_offset(d_attr);
>
> - pm_runtime_get_sync(dev->parent);
> + ret = pm_runtime_resume_and_get(dev->parent);
> + if (ret < 0)
> + return ret;
> val = etmv4_cross_read(drvdata, offset);
> pm_runtime_put_sync(dev->parent);
>
> diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
> index 0abc11f0690c5272ebd55df9e98544e3b401cfe6..5824a1e4d046a3caf5b32ed1d8526b8bd7e9ca76 100644
> --- a/drivers/hwtracing/coresight/coresight-funnel.c
> +++ b/drivers/hwtracing/coresight/coresight-funnel.c
> @@ -190,9 +190,12 @@ static ssize_t funnel_ctrl_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> u32 val;
> + int ret;
> struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
>
> - pm_runtime_get_sync(dev->parent);
> + ret = pm_runtime_resume_and_get(dev->parent);
> + if (ret < 0)
> + return ret;
>
> val = get_funnel_ctrl_hw(drvdata);
>
> diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
> index 4e860519a73f6fff640090cf58298b89a31e6359..b9f15990ed994ea827c8e237d764e74d8d231ddd 100644
> --- a/drivers/hwtracing/coresight/coresight-stm.c
> +++ b/drivers/hwtracing/coresight/coresight-stm.c
> @@ -196,6 +196,7 @@ static int stm_enable(struct coresight_device *csdev, struct perf_event *event,
> __maybe_unused struct coresight_path *path)
> {
> struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> + int ret;
>
> if (mode != CS_MODE_SYSFS)
> return -EINVAL;
> @@ -205,7 +206,11 @@ static int stm_enable(struct coresight_device *csdev, struct perf_event *event,
> return -EBUSY;
> }
>
> - pm_runtime_get_sync(csdev->dev.parent);
> + ret = pm_runtime_resume_and_get(csdev->dev.parent);
> + if (ret < 0) {
> + coresight_set_mode(csdev, CS_MODE_DISABLED);
> + return ret;
> + }
>
> spin_lock(&drvdata->spinlock);
> stm_enable_hw(drvdata);
> diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
> index 4b010f8bc4c08da31b3d295be6c37b6d941629d2..5849dfbd9d0bd3ad10734919f78bc39cc968539c 100644
> --- a/drivers/hwtracing/coresight/coresight-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c
> @@ -17,8 +17,12 @@ ssize_t coresight_simple_show_pair(struct device *_dev,
> struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
> struct cs_pair_attribute *cs_attr = container_of(attr, struct cs_pair_attribute, attr);
> u64 val;
> + int ret;
> +
> + ret = pm_runtime_resume_and_get(_dev->parent);
> + if (ret < 0)
> + return ret;
>
> - pm_runtime_get_sync(_dev->parent);
> val = csdev_access_relaxed_read_pair(&csdev->access, cs_attr->lo_off, cs_attr->hi_off);
> pm_runtime_put_sync(_dev->parent);
> return sysfs_emit(buf, "0x%llx\n", val);
> @@ -31,8 +35,11 @@ ssize_t coresight_simple_show32(struct device *_dev,
> struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
> struct cs_off_attribute *cs_attr = container_of(attr, struct cs_off_attribute, attr);
> u64 val;
> + int ret;
>
> - pm_runtime_get_sync(_dev->parent);
> + ret = pm_runtime_resume_and_get(_dev->parent);
> + if (ret < 0)
> + return ret;
> val = csdev_access_relaxed_read32(&csdev->access, cs_attr->off);
> pm_runtime_put_sync(_dev->parent);
> return sysfs_emit(buf, "0x%llx\n", val);
>
> ---
> base-commit: 08df884136f1c1197bab2a27814404fd329d9aac
> change-id: 20260911-b4-coresight-runtime-pm-failures-70f250927aeb
>
> Best regards,
> --
> Yuanfang Zhang <yuanfang@qti.qualcomm.com>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] coresight: handle runtime PM resume failures
2026-09-11 10:28 [PATCH] coresight: handle runtime PM resume failures Yuanfang Zhang
2026-09-11 13:11 ` Ulf Hansson
@ 2026-09-16 10:30 ` Leo Yan
1 sibling, 0 replies; 3+ messages in thread
From: Leo Yan @ 2026-09-16 10:30 UTC (permalink / raw)
To: Yuanfang Zhang
Cc: Suzuki K Poulose, Mike Leach, James Clark, Alexander Shishkin,
Maxime Coquelin, Alexandre Torgue, kernel, coresight,
linux-arm-kernel, linux-kernel, linux-stm32
On Fri, Sep 11, 2026 at 03:28:52AM -0700, Yuanfang Zhang wrote:
[...]
> Replace the remaining pm_runtime_get_sync() calls with
> pm_runtime_resume_and_get(), which restores the runtime PM usage count
> when resume fails. Abort before accessing hardware and propagate the
> error to the caller.
The change makes sense to me.
> In coresight_get_ref(), unwind the module and device references.
Sashiko reported a pre-existing issue where the callers don't handle
errors returned by coresight_get_ref() [1]. In this case, we need to
remove nodes from path->path_list and release them. However, this
should be done in a separate patch.
[1] https://sashiko.dev/#/patchset/20260911-b4-coresight-runtime-pm-failures-v1-1-acdf49756e11%40qti.qualcomm.com
> Signed-off-by: Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>
Thanks for the fix! Feel free to add:
Reviewed-by: Leo Yan <leo.yan@arm.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-09-16 10:30 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2026-09-11 10:28 [PATCH] coresight: handle runtime PM resume failures Yuanfang Zhang
2026-09-11 13:11 ` Ulf Hansson
2026-09-16 10:30 ` Leo Yan
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®