Re: [PATCH] clk: imx: scu: fix autosuspend cleanup on probe failure

Johan Hovold <[email protected]>
Newsgroups gmane.linux.kernel.stable,gmane.linux.kernel.clk,gmane.linux.ports.arm.kernel,gmane.linux.kernel
Message-ID <[email protected]>
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.

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: [email protected]
> Signed-off-by: Guangshuo Li <[email protected]>

Johan
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