Commit 878e845d authored by Pin-yen Lin's avatar Pin-yen Lin Committed by Stephen Boyd
Browse files

clk: mediatek: mt8183: Only enable runtime PM on mt8183-mfgcfg 



Commit 2f7b1d8b ("clk: mediatek: Do a runtime PM get on controllers
during probe") enabled runtime PM for all mediatek clock controllers,
but this introduced an issue on the resume path.

If a device resumes earlier than the clock controller and calls
clk_prepare() when runtime PM is enabled on the controller, it will end
up calling clk_pm_runtime_get(). But the subsequent
pm_runtime_resume_and_get() call will fail because the runtime PM is
temporarily disabled during suspend.

To workaround this, introduce a need_runtime_pm flag and only enable it
on mt8183-mfgcfg, which is the driver that observed deadlock previously.
Hopefully mt8183-cfgcfg won't run into the issue at the resume stage
because the GPU should have stopped rendering before the system calls
suspend.

Fixes: 2f7b1d8b ("clk: mediatek: Do a runtime PM get on controllers during probe")
Signed-off-by: default avatarPin-yen Lin <treapking@chromium.org>
Link: https://lore.kernel.org/r/20240613120357.1043342-1-treapking@chromium.org


Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent f7275fdf

drivers/clk/mediatek/clk-mt8183-mfgcfg.c

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ static const struct mtk_gate mfg_clks[] = { 
static const struct mtk_clk_desc mfg_desc = {

	.clks = mfg_clks,

	.num_clks = ARRAY_SIZE(mfg_clks),

	.need_runtime_pm = true,

};



static const struct of_device_id of_match_clk_mt8183_mfg[] = {

drivers/clk/mediatek/clk-mtk.c

+14 −10
Original line number Diff line number Diff line
@@ -496,6 +496,7 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, 
	}





	if (mcd->need_runtime_pm) {

		devm_pm_runtime_enable(&pdev->dev);

		/*

		 * Do a pm_runtime_resume_and_get() to workaround a possible
@@ -504,6 +505,7 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, 
		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;
@@ -585,6 +587,7 @@ 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;
@@ -618,6 +621,7 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, 
	if (mcd->shared_io && base)

		iounmap(base);



	if (mcd->need_runtime_pm)

		pm_runtime_put(&pdev->dev);

	return r;

}

drivers/clk/mediatek/clk-mtk.h

+2 −0
Original line number Diff line number Diff line
@@ -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);