Re: [PATCH v2 2/2] pmdomain: imx: scu-pd: allow building as a module

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Changing IMX_SCU_PD to a tristate exposes a critical probe order race condition with the SCU clock driver, leading to unpowered hardware and system crashes.
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--- Patch [2]: [PATCH v2 2/2] pmdomain: imx: scu-pd: allow building as a module ---
commit d3bf08bb865becc5d6316a0d9e70a9dbcc5e5ef3
Author: Zhipeng Wang <zhipeng.wang_1@nxp.com>

pmdomain: imx: scu-pd: allow building as a module

This commit converts CONFIG_IMX_SCU_PD to tristate to allow building as a
loadable module, which is required for Android Generic Kernel Image (GKI)
support. It adds MODULE_DEVICE_TABLE and a module_init function since the
driver cannot be safely removed.

> diff --git a/drivers/pmdomain/imx/Kconfig b/drivers/pmdomain/imx/Kconfig
> index 00203615c65e9..472e9dec6bd4e 100644
> --- a/drivers/pmdomain/imx/Kconfig
> +++ b/drivers/pmdomain/imx/Kconfig
> @@ -21,7 +21,7 @@ config IMX9_BLK_CTRL
>  	depends on PM_GENERIC_DOMAINS
>  
>  config IMX_SCU_PD
> -	bool "IMX SCU Power Domain driver"
> +	tristate "IMX SCU Power Domain driver"

[Severity: High]
Does allowing this driver to be built as a module expose a probe order
race condition with the SCU clock driver?

If the power domain driver is loaded asynchronously after the SCU clock
driver (clk-imx8qxp), the clock-controller DT node lacks a power-domains
property, so fw_devlink cannot enforce the correct probe order.

In this scenario, the clock driver manually looks up the power domain
provider using of_find_compatible_node() and calls of_genpd_add_device().
If the power domain driver has not probed yet, genpd_get_from_provider()
will fail and return -ENOENT.

The clock driver ignores this error in imx_clk_scu_alloc_dev() and
registers the clock device without attaching it to the PM domain. When
the clock is later requested, the Common Clock Framework's
pm_runtime_resume_and_get() will succeed passively because there is no
attached PM domain.

Can this lead to system crashes or hardware access faults due to
accessing unpowered hardware?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260722032321.2693300-1-Zhipeng.wang_1@oss.nxp.com?part=2