From: Pin-yen Lin <treapking@chromium.org> To: Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@kernel.org>, Matthias Brugger <matthias.bgg@gmail.com>, AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: "Chen-Yu Tsai" <wenst@chromium.org>, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, "Pin-yen Lin" <treapking@chromium.org>, "Weiyi Lu" <weiyi.lu@mediatek.com>, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, "Bosi Zhang" <u201911157@hust.edu.cn>, "Nicolas Boichat" <drinkcat@chromium.org>, "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> Subject: [PATCH v4] clk: mediatek: Do a runtime PM get on controllers during probe Date: Tue, 12 Mar 2024 19:51:55 +0800 [thread overview] Message-ID: <20240312115249.3341654-1-treapking@chromium.org> (raw) mt8183-mfgcfg has a mutual dependency with genpd during the probing stage, which leads to a deadlock in the following call stack: CPU0: genpd_lock --> clk_prepare_lock genpd_power_off_work_fn() genpd_lock() generic_pm_domain::power_off() clk_unprepare() clk_prepare_lock() CPU1: clk_prepare_lock --> genpd_lock clk_register() __clk_core_init() clk_prepare_lock() clk_pm_runtime_get() genpd_lock() Do a runtime PM get at the probe function to make sure clk_register() won't acquire the genpd lock. Instead of only modifying mt8183-mfgcfg, do this on all mediatek clock controller probings because we don't believe this would cause any regression. Verified on MT8183 and MT8192 Chromebooks. Fixes: acddfc2c261b ("clk: mediatek: Add MT8183 clock support") Signed-off-by: Pin-yen Lin <treapking@chromium.org> --- v3: https://lore.kernel.org/all/20240108081834.408403-1-treapking@chromium.org/ Changes in v4: - Remove the need_runtime_pm flag and apply this to all mtk controllers Changes in v3: - Update the commit message and the comments before runtime PM call Changes in v2: - Fix the order of error handling - Update the commit message and add a comment before the runtime PM call drivers/clk/mediatek/clk-mtk.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c index 2e55368dc4d8..bd37ab4d1a9b 100644 --- a/drivers/clk/mediatek/clk-mtk.c +++ b/drivers/clk/mediatek/clk-mtk.c @@ -13,6 +13,7 @@ #include <linux/of.h> #include <linux/of_address.h> #include <linux/platform_device.h> +#include <linux/pm_runtime.h> #include <linux/slab.h> #include "clk-mtk.h" @@ -494,6 +495,16 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, return IS_ERR(base) ? PTR_ERR(base) : -ENOMEM; } + + 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; num_clks += mcd->num_fixed_clks + mcd->num_factor_clks; @@ -574,6 +585,8 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, goto unregister_clks; } + pm_runtime_put(&pdev->dev); + return r; unregister_clks: @@ -604,6 +617,8 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, free_base: if (mcd->shared_io && base) iounmap(base); + + pm_runtime_put(&pdev->dev); return r; } -- 2.44.0.278.ge034bb2e1d-goog
WARNING: multiple messages have this Message-ID (diff)
From: Pin-yen Lin <treapking@chromium.org> To: Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@kernel.org>, Matthias Brugger <matthias.bgg@gmail.com>, AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: "Chen-Yu Tsai" <wenst@chromium.org>, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, "Pin-yen Lin" <treapking@chromium.org>, "Weiyi Lu" <weiyi.lu@mediatek.com>, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, "Bosi Zhang" <u201911157@hust.edu.cn>, "Nicolas Boichat" <drinkcat@chromium.org>, "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> Subject: [PATCH v4] clk: mediatek: Do a runtime PM get on controllers during probe Date: Tue, 12 Mar 2024 19:51:55 +0800 [thread overview] Message-ID: <20240312115249.3341654-1-treapking@chromium.org> (raw) mt8183-mfgcfg has a mutual dependency with genpd during the probing stage, which leads to a deadlock in the following call stack: CPU0: genpd_lock --> clk_prepare_lock genpd_power_off_work_fn() genpd_lock() generic_pm_domain::power_off() clk_unprepare() clk_prepare_lock() CPU1: clk_prepare_lock --> genpd_lock clk_register() __clk_core_init() clk_prepare_lock() clk_pm_runtime_get() genpd_lock() Do a runtime PM get at the probe function to make sure clk_register() won't acquire the genpd lock. Instead of only modifying mt8183-mfgcfg, do this on all mediatek clock controller probings because we don't believe this would cause any regression. Verified on MT8183 and MT8192 Chromebooks. Fixes: acddfc2c261b ("clk: mediatek: Add MT8183 clock support") Signed-off-by: Pin-yen Lin <treapking@chromium.org> --- v3: https://lore.kernel.org/all/20240108081834.408403-1-treapking@chromium.org/ Changes in v4: - Remove the need_runtime_pm flag and apply this to all mtk controllers Changes in v3: - Update the commit message and the comments before runtime PM call Changes in v2: - Fix the order of error handling - Update the commit message and add a comment before the runtime PM call drivers/clk/mediatek/clk-mtk.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c index 2e55368dc4d8..bd37ab4d1a9b 100644 --- a/drivers/clk/mediatek/clk-mtk.c +++ b/drivers/clk/mediatek/clk-mtk.c @@ -13,6 +13,7 @@ #include <linux/of.h> #include <linux/of_address.h> #include <linux/platform_device.h> +#include <linux/pm_runtime.h> #include <linux/slab.h> #include "clk-mtk.h" @@ -494,6 +495,16 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, return IS_ERR(base) ? PTR_ERR(base) : -ENOMEM; } + + 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; num_clks += mcd->num_fixed_clks + mcd->num_factor_clks; @@ -574,6 +585,8 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, goto unregister_clks; } + pm_runtime_put(&pdev->dev); + return r; unregister_clks: @@ -604,6 +617,8 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev, free_base: if (mcd->shared_io && base) iounmap(base); + + pm_runtime_put(&pdev->dev); return r; } -- 2.44.0.278.ge034bb2e1d-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2024-03-12 11:52 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-03-12 11:51 Pin-yen Lin [this message] 2024-03-12 11:51 ` [PATCH v4] clk: mediatek: Do a runtime PM get on controllers during probe Pin-yen Lin 2024-03-12 14:41 ` AngeloGioacchino Del Regno 2024-03-12 14:41 ` AngeloGioacchino Del Regno 2024-04-11 3:48 ` Stephen Boyd 2024-04-11 3:48 ` Stephen Boyd
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