drivers/clk/imx/clk-scu.c | 4 ++++ 1 file changed, 4 insertions(+)
imx_clk_scu_probe() calls pm_runtime_use_autosuspend() for non-CPU
clocks, but its probe failure paths do not call the matching
pm_runtime_dont_use_autosuspend() before disabling runtime PM.
If the autosuspend delay is set to a negative value while autosuspend
is enabled, the runtime PM core increments usage_count to prevent
runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
during cleanup, this reference is not dropped and usage_count remains
unbalanced.
Add the missing pm_runtime_dont_use_autosuspend() calls to the probe
failure paths before disabling runtime PM.
This issue was found by manual code inspection.
Fixes: 78edeb080330 ("clk: imx: scu: add runtime pm support")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
drivers/clk/imx/clk-scu.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c
index 9b33df9967ec..6d29fcc2306d 100644
--- a/drivers/clk/imx/clk-scu.c
+++ b/drivers/clk/imx/clk-scu.c
@@ -542,6 +542,7 @@ static int imx_clk_scu_probe(struct platform_device *pdev)
ret = pm_runtime_resume_and_get(dev);
if (ret) {
pm_genpd_remove_device(dev);
+ pm_runtime_dont_use_autosuspend(dev);
pm_runtime_disable(dev);
return ret;
}
@@ -550,6 +551,9 @@ static int imx_clk_scu_probe(struct platform_device *pdev)
hw = __imx_clk_scu(dev, clk->name, clk->parents, clk->num_parents,
clk->rsrc, clk->clk_type);
if (IS_ERR(hw)) {
+ if (!(clk->rsrc == IMX_SC_R_A35 || clk->rsrc == IMX_SC_R_A53 ||
+ clk->rsrc == IMX_SC_R_A72))
+ pm_runtime_dont_use_autosuspend(dev);
pm_runtime_disable(dev);
return PTR_ERR(hw);
}
--
2.43.0On Sat, Aug 08, 2026 at 04:29:33PM +0800, Guangshuo Li wrote:
> imx_clk_scu_probe() calls pm_runtime_use_autosuspend() for non-CPU
> clocks, but its probe failure paths do not call the matching
> pm_runtime_dont_use_autosuspend() before disabling runtime PM.
>
> If the autosuspend delay is set to a negative value while autosuspend
> is enabled, the runtime PM core increments usage_count to prevent
> runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
> during cleanup, this reference is not dropped and usage_count remains
> unbalanced.
As I've explained elsewhere, this is just misleading. There is no usage
count leak here as the count is balanced whenever the user re-enables
autosuspend through sysfs (by writing a non-negative timeout).
Drivers should clean up after themselves and disable autosuspend, but
this is more of a clean up than a fix and should not be backported.
You've sent upwards of 60 of these in the matter of just a few days,
some of which have even been picked up. Please send follow-ups (replies
or v2s) as soon as possible to prevent further of these from getting
merged.
> Add the missing pm_runtime_dont_use_autosuspend() calls to the probe
> failure paths before disabling runtime PM.
>
> This issue was found by manual code inspection.
>
> Fixes: 78edeb080330 ("clk: imx: scu: add runtime pm support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Johan
Hi,
On Sat, Aug 08, 2026 at 04:29:33PM +0800, Guangshuo Li wrote:
>imx_clk_scu_probe() calls pm_runtime_use_autosuspend() for non-CPU
>clocks, but its probe failure paths do not call the matching
>pm_runtime_dont_use_autosuspend() before disabling runtime PM.
>
>If the autosuspend delay is set to a negative value while autosuspend
>is enabled, the runtime PM core increments usage_count to prevent
>runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
>during cleanup, this reference is not dropped and usage_count remains
>unbalanced.
>
>Add the missing pm_runtime_dont_use_autosuspend() calls to the probe
>failure paths before disabling runtime PM.
>
>This issue was found by manual code inspection.
>
>Fixes: 78edeb080330 ("clk: imx: scu: add runtime pm support")
>Cc: stable@vger.kernel.org
>Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
>---
> drivers/clk/imx/clk-scu.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
>diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c
>index 9b33df9967ec..6d29fcc2306d 100644
>--- a/drivers/clk/imx/clk-scu.c
>+++ b/drivers/clk/imx/clk-scu.c
>@@ -542,6 +542,7 @@ static int imx_clk_scu_probe(struct platform_device *pdev)
> ret = pm_runtime_resume_and_get(dev);
> if (ret) {
> pm_genpd_remove_device(dev);
>+ pm_runtime_dont_use_autosuspend(dev);
> pm_runtime_disable(dev);
> return ret;
> }
>@@ -550,6 +551,9 @@ static int imx_clk_scu_probe(struct platform_device *pdev)
> hw = __imx_clk_scu(dev, clk->name, clk->parents, clk->num_parents,
> clk->rsrc, clk->clk_type);
> if (IS_ERR(hw)) {
>+ if (!(clk->rsrc == IMX_SC_R_A35 || clk->rsrc == IMX_SC_R_A53 ||
>+ clk->rsrc == IMX_SC_R_A72))
>+ pm_runtime_dont_use_autosuspend(dev);
> pm_runtime_disable(dev);
> return PTR_ERR(hw);
This is not complete fix. I just write one, see below:
imx_clk_scu_probe() sets up runtime PM for non-CPU clocks by calling
pm_runtime_use_autosuspend(), pm_runtime_enable(), and
pm_runtime_resume_and_get(). The probe failure paths do not properly
undo these operations:
1. When pm_runtime_resume_and_get() fails, pm_runtime_dont_use_autosuspend()
is not called before pm_runtime_disable(), leaving the autosuspend
setting unbalanced.
2. When __imx_clk_scu() fails, pm_runtime_disable() is called
unconditionally even for CPU clocks, which never had pm_runtime_enable()
called, causing an unbalanced disable depth. For non-CPU clocks,
neither pm_runtime_put_noidle() nor pm_runtime_dont_use_autosuspend()
are called, leaving both the usage count and autosuspend setting
unbalanced.
Fix the first path by adding pm_runtime_dont_use_autosuspend() before
pm_runtime_disable(). Fix the second path by guarding all three cleanup
calls — pm_runtime_put_noidle(), pm_runtime_dont_use_autosuspend(), and
pm_runtime_disable() — with the non-CPU clock check.
Fixes: 78edeb080330 ("clk: imx: scu: add runtime pm support")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c
index 9b33df9967ece..63ab4801ddaa7 100644
--- a/drivers/clk/imx/clk-scu.c
+++ b/drivers/clk/imx/clk-scu.c
@@ -542,6 +542,7 @@ static int imx_clk_scu_probe(struct platform_device *pdev)
ret = pm_runtime_resume_and_get(dev);
if (ret) {
pm_genpd_remove_device(dev);
+ pm_runtime_dont_use_autosuspend(dev);
pm_runtime_disable(dev);
return ret;
}
@@ -550,7 +551,12 @@ static int imx_clk_scu_probe(struct platform_device *pdev)
hw = __imx_clk_scu(dev, clk->name, clk->parents, clk->num_parents,
clk->rsrc, clk->clk_type);
if (IS_ERR(hw)) {
- pm_runtime_disable(dev);
+ if (!((clk->rsrc == IMX_SC_R_A35) || (clk->rsrc == IMX_SC_R_A53) ||
+ (clk->rsrc == IMX_SC_R_A72))) {
+ pm_runtime_put_noidle(dev);
+ pm_runtime_dont_use_autosuspend(dev);
+ pm_runtime_disable(dev);
+ }
return PTR_ERR(hw);
}
Regards,
Peng
> }
>--
>2.43.0
>
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