Re: [PATCH] dmaengine: ste_dma40: fix autosuspend cleanup on probe failure

Linus Walleij <[email protected]> Mon, 10 Aug 2026 00:15:55 +0200

Newsgroups	org.kernel.vger.dmaengine,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel,org.kernel.vger.stable
Message-ID	<CAD++jLnAr8jcnqrFe+h5tjw_TJSuXChSS8PMd8WX5LAO5Q5PNA@mail.gmail.com>

On Sat, Aug 8, 2026 at 12:57 PM Guangshuo Li <[email protected]> wrote:

> d40_probe() calls pm_runtime_use_autosuspend(), but its error path does
> 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() call to the probe
> failure path before disabling runtime PM.
>
> This issue was found by manual code inspection.
>
> Fixes: 8d318a50b3d7 ("DMAENGINE: Support for ST-Ericssons DMA40 block v3")
> Cc: [email protected]
> Signed-off-by: Guangshuo Li <[email protected]>

Reviewed-by: Linus Walleij <[email protected]>

Yours,
Linus Walleij