Re: [PATCH v4] clk: mediatek: Do a runtime PM get on controllers during probe

[AngeloGioacchino Del Regno]

Il 12/03/24 12:51, Pin-yen Lin ha scritto:
> mt8183-mfgcfg has a mutual dependency with genpd during the probing
> stage, which leads to a deadlock in the following call stack:
>
> CPU0:  genpd_lock --> clk_prepare_lock
> genpd_power_off_work_fn()
>   genpd_lock()
>   generic_pm_domain::power_off()
>      clk_unprepare()
>        clk_prepare_lock()
>
> CPU1: clk_prepare_lock --> genpd_lock
> clk_register()
>    __clk_core_init()
>      clk_prepare_lock()
>      clk_pm_runtime_get()
>        genpd_lock()
>
> Do a runtime PM get at the probe function to make sure clk_register()
> won't acquire the genpd lock. Instead of only modifying mt8183-mfgcfg,
> do this on all mediatek clock controller probings because we don't
> believe this would cause any regression.
>
> Verified on MT8183 and MT8192 Chromebooks.
>
> Fixes: acddfc2c261b ("clk: mediatek: Add MT8183 clock support")
> Signed-off-by: Pin-yen Lin <treapking@xxxxxxxxxxxx>

MT8195 Cherry Tomato - no issues as well.

Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>