Re: [PATCH v3 1/2] clk: mediatek: Introduce need_pm_runtime to mtk_clk_desc

Chen-Yu Tsai
2024-02-23T04:28:18Z

On Mon, Jan 8, 2024 at 4:18 PM Pin-yen Lin <treapking@chromium.org> wrote:
>
> Introduce a new need_pm_runtime variable to mtk_clk_desc to indicate
> this clock controller needs runtime PM for its operations.
> Also do a runtime PM get on the clock controller during the
> probing stage to workaround a possible deadlock.
>
> Signed-off-by: Pin-yen Lin <treapking@chromium.org>

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>

The patch itself looks fine.

Besides the MT8183 MFG clock issues, we do actually need this for the
MT8192 ADSP clock. Its power domain is not enabled by default.

> ---
>
> Changes in v3:
> - Update the commit message and the comments before runtime PM call
>
> Changes in v2:
> - Fix the order of error handling
> - Update the commit message and add a comment before the runtime PM call
>
> drivers/clk/mediatek/clk-mtk.c | 19 +++++++++++++++++++
> drivers/clk/mediatek/clk-mtk.h | 2 ++
> 2 files changed, 21 insertions(+)
>
> diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c
> index 2e55368dc4d8..ba1d1c495bc2 100644
> --- a/drivers/clk/mediatek/clk-mtk.c
> +++ b/drivers/clk/mediatek/clk-mtk.c
> @@ -13,6 +13,7 @@
> #include <linux/of.h>
> #include <linux/of_address.h>
> #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> #include <linux/slab.h>
>
> #include "clk-mtk.h"
> @@ -494,6 +495,18 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
> return IS_ERR(base) ? PTR_ERR(base) : -ENOMEM;
> }
>
> +
> + if (mcd->need_runtime_pm) {
> + devm_pm_runtime_enable(&pdev->dev);
> + /*
> + * Do a pm_runtime_resume_and_get() to workaround a possible
> + * deadlock between clk_register() and the genpd framework.
> + */
> + r = pm_runtime_resume_and_get(&pdev->dev);
> + if (r)
> + return r;
> + }
> +
> /* Calculate how many clk_hw_onecell_data entries to allocate */
> num_clks = mcd->num_clks + mcd->num_composite_clks;
> num_clks += mcd->num_fixed_clks + mcd->num_factor_clks;
> @@ -574,6 +587,9 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
> goto unregister_clks;
> }
>
> + if (mcd->need_runtime_pm)
> + pm_runtime_put(&pdev->dev);
> +
> return r;
>
> unregister_clks:
> @@ -604,6 +620,9 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
> free_base:
> if (mcd->shared_io && base)
> iounmap(base);
> +
> + if (mcd->need_runtime_pm)
> + pm_runtime_put(&pdev->dev);
> return r;
> }
>
> diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
> index 22096501a60a..c17fe1c2d732 100644
> --- a/drivers/clk/mediatek/clk-mtk.h
> +++ b/drivers/clk/mediatek/clk-mtk.h
> @@ -237,6 +237,8 @@ struct mtk_clk_desc {
>
> int (*clk_notifier_func)(struct device *dev, struct clk *clk);
> unsigned int mfg_clk_idx;
> +
> + bool need_runtime_pm;
> };
>
> int mtk_clk_pdev_probe(struct platform_device *pdev);
> --
> 2.43.0.472.g3155946c3a-goog
>