Patch "clk: mediatek: mt8183: Only enable runtime PM on mt8183-mfgcfg" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     clk-mediatek-mt8183-only-enable-runtime-pm-on-mt8183.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6e832ddc248c88673e6b2b9e7004c33ee867c4d8
Author: Pin-yen Lin <treapking@xxxxxxxxxxxx>
Date:   Thu Jun 13 20:02:28 2024 +0800

    clk: mediatek: mt8183: Only enable runtime PM on mt8183-mfgcfg
    
    [ 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@xxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240613120357.1043342-1-treapking@xxxxxxxxxxxx
    Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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);