Re: [PATCH] dmaengine: pl330: fix autosuspend cleanup during removal

[Johan Hovold <johan@kernel.org>]

On Sat, Aug 08, 2026 at 05:44:52PM +0800, Guangshuo Li wrote:
> pl330_probe() calls pm_runtime_use_autosuspend(), but pl330_remove()
> does not call the matching pm_runtime_dont_use_autosuspend() when
> removing the device.
> 
> 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 teardown, 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 a just a few days,
some 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() call before restoring
> the runtime PM usage reference in the remove path.
> 
> This issue was found by manual code inspection.
> 
> Fixes: ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>

Johan