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

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>

diff --git a/drivers/clk/mediatek/clk-mt8183-mfgcfg.c b/drivers/clk/mediatek/clk-mt8183-mfgcfg.c
index ba504e1..62d876e 100644 (file)
--- 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 bd37ab4..ba1d1c4 100644 (file)
--- 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 @@ free_base:
        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 2209650..c17fe1c 100644 (file)
--- 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);