Re: [PATCH v2 2/9] mailbox: imx: Use devm_pm_runtime_enable()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Double clk_disable_unprepare() on the devm_mbox_controller_register() error path.
--

commit 6af621bbda5cc8cf36298bb4f6590f6101b7c4a5
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

mailbox: imx: Use devm_pm_runtime_enable()

This commit mitigates early usage of the device before probe completes
by delaying the pm_runtime_enable() into the removal path. It also moves
devm_mbox_controller_register() to occur after the pm-runtime handling.

> diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
> --- a/drivers/mailbox/imx-mailbox.c
> +++ b/drivers/mailbox/imx-mailbox.c
[ ... ]
> @@ -965,28 +965,28 @@ static int imx_mu_probe(struct platform_device *pdev)
[ ... ]
>  	ret = pm_runtime_put_sync(dev);
>  	if (ret < 0)
> -		goto disable_runtime_pm;
> +		goto disable_clk;
>  
>  	clk_disable_unprepare(priv->clk);
>  
> +	ret = devm_mbox_controller_register(dev, &priv->mbox);
> +	if (ret)
> +		goto disable_clk;

[Severity: High]
Does this error path cause a double clock disable?

If devm_mbox_controller_register() fails here, the code jumps to the
disable_clk label. However, clk_disable_unprepare(priv->clk) has already
been called just above this registration attempt. This means the error path
will disable the clock a second time, which could cause a reference count
underflow and potentially disable shared clocks.

> +
> +	of_platform_populate(dev->of_node, NULL, NULL, dev);
> +
>  	return 0;
>  
> -disable_runtime_pm:
> -	pm_runtime_disable(dev);
>  disable_clk:
>  	clk_disable_unprepare(priv->clk);
>  	return ret;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260603-imx_mbox_rproc-v2-0-a0059dc3b69a@linutronix.de?part=2