6.1-stable review patch. If anyone has any objections, please let me know.
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From: Pin-yen Lin treapking@chromium.org
[ Upstream commit 878e845d8db04df9ff3bbbaac09d335b24153704 ]
Commit 2f7b1d8b5505 ("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: 2f7b1d8b5505 ("clk: mediatek: Do a runtime PM get on controllers during probe") Signed-off-by: Pin-yen Lin treapking@chromium.org Link: https://lore.kernel.org/r/20240613120357.1043342-1-treapking@chromium.org Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/mediatek/clk-mt8183-mfgcfg.c | 1 + drivers/clk/mediatek/clk-mtk.c | 24 ++++++++++++++---------- drivers/clk/mediatek/clk-mtk.h | 2 ++ 3 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/drivers/clk/mediatek/clk-mt8183-mfgcfg.c b/drivers/clk/mediatek/clk-mt8183-mfgcfg.c index 730c9ae5ea124..50ccd59794464 100644 --- a/drivers/clk/mediatek/clk-mt8183-mfgcfg.c +++ b/drivers/clk/mediatek/clk-mt8183-mfgcfg.c @@ -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[] = { diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c index 42ae5c0d56467..9dbfc11d5c591 100644 --- a/drivers/clk/mediatek/clk-mtk.c +++ b/drivers/clk/mediatek/clk-mtk.c @@ -472,14 +472,16 @@ int mtk_clk_simple_probe(struct platform_device *pdev) }
- 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; + 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; @@ -550,7 +552,8 @@ int mtk_clk_simple_probe(struct platform_device *pdev) goto unregister_clks; }
- pm_runtime_put(&pdev->dev); + if (mcd->need_runtime_pm) + pm_runtime_put(&pdev->dev);
return r;
@@ -578,7 +581,8 @@ int mtk_clk_simple_probe(struct platform_device *pdev) if (mcd->shared_io && base) iounmap(base);
- pm_runtime_put(&pdev->dev); + if (mcd->need_runtime_pm) + pm_runtime_put(&pdev->dev); return r; } EXPORT_SYMBOL_GPL(mtk_clk_simple_probe); diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h index 361de8078df01..65c24ab6c9470 100644 --- a/drivers/clk/mediatek/clk-mtk.h +++ b/drivers/clk/mediatek/clk-mtk.h @@ -210,6 +210,8 @@ 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_simple_probe(struct platform_device *pdev);