| Message ID | 20240613120357.1043342-1-treapking@chromium.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | clk: mediatek: mt8183: Only enable runtime PM on mt8183-mfgcfg | expand |
Quoting Pin-yen Lin (2024-06-13 05:02:28) > 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> > > --- Applied to clk-fixes
diff --git a/drivers/clk/mediatek/clk-mt8183-mfgcfg.c b/drivers/clk/mediatek/clk-mt8183-mfgcfg.c index c89c3d58fedc..b1e802bbfaef 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 bd37ab4d1a9b..ba1d1c495bc2 100644 --- a/drivers/clk/mediatek/clk-mtk.c +++ b/drivers/clk/mediatek/clk-mtk.c @@ -496,14 +496,16 @@ static 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; @@ -585,7 +587,8 @@ static 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; @@ -618,7 +621,8 @@ static 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; } 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);
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> --- 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(-)