Re: [PATCH v3] pmdomain: imx8m-blk-ctrl: Serialize power on/off across sibling domains

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] cleanup: mixing goto-based cleanup with guard() in imx8m_blk_ctrl_power_on
--

commit 3b7233b47967e5b29603c44328524d995a2c4def
Author: Ming Qian <ming.qian@oss.nxp.com>

pmdomain: imx8m-blk-ctrl: Serialize power on/off across sibling domains

On i.MX8MP the VPU blk-ctrl exposes G1, G2 and VC8000E as three separate
genpds, each serialized only by its own genpd lock, so their power_on and
power_off callbacks can run concurrently on SMP. Serialize the blk-ctrl
reset sequence with a per-blk-ctrl mutex to prevent sibling transitions
from disturbing shared clock and handshake timing.

> diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> index 479789009c7f4..f8105e87ea3c0 100644
> --- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> +++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> @@ -98,6 +105,8 @@ static int imx8m_blk_ctrl_power_on(struct generic_pm_domain *genpd)
>  	struct imx8m_blk_ctrl *bc = domain->bc;
>  	int ret;
>  
> +	guard(mutex)(&bc->power_lock);
> +
>  	/* make sure bus domain is awake */
>  	ret = pm_runtime_get_sync(bc->bus_power_dev);
>  	if (ret < 0) {

[Severity: Low]
This isn't a bug, but does this mix goto-based cleanup with guard() in the
same function?

The subsystem guidelines in include/linux/cleanup.h state that goto and
cleanup helpers should never be mixed in the same function.

imx8m_blk_ctrl_power_on() still has goto labels for manual unwinding:

	/* power up upstream GPC domain */
	ret = pm_runtime_get_sync(domain->power_dev);
	if (ret < 0) {
		dev_err(bc->dev, "failed to power up peripheral domain\n");
		goto clk_disable;
	}

	...

clk_disable:
	clk_bulk_disable_unprepare(data->num_clks, domain->clks);
bus_put:
	pm_runtime_put(bc->bus_power_dev);

	return ret;

Should the existing resources be converted to scope-based cleanup, or should
this lock be managed manually to avoid mixing the two patterns?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260921-imx8mp-blk-ctrl-v3-1-c86b0a9d4781@oss.nxp.com?part=1