6.6-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 2f7b1d8b5505efb0057cd1ab85fca206063ea4c3 ]
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
Link: https://lore.kernel.org/r/20240312115249.3341654-1-treapking@chromium.org Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Tested-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 2e55368dc4d82..bd37ab4d1a9bb 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; }