Re: [PATCH] clk: imx: scu: fix autosuspend cleanup on probe failure
From: Peng Fan <hidden>
Date: 2026-08-10 12:59:34
Also in:
imx, linux-clk, lkml, stable
Subsystem:
common clk framework, nxp i.mx clock drivers, the rest · Maintainers:
Stephen Boyd, Brian Masney, Jerome Brunet, Abel Vesa, Linus Torvalds
Hi, On Sat, Aug 08, 2026 at 04:29:33PM +0800, Guangshuo Li wrote:
quoted hunk ↗ jump to hunk
imx_clk_scu_probe() calls pm_runtime_use_autosuspend() for non-CPU clocks, but its probe failure paths do not call the matching pm_runtime_dont_use_autosuspend() before disabling runtime PM. If the autosuspend delay is set to a negative value while autosuspend is enabled, the runtime PM core increments usage_count to prevent runtime suspend. Without calling pm_runtime_dont_use_autosuspend() during cleanup, this reference is not dropped and usage_count remains unbalanced. Add the missing pm_runtime_dont_use_autosuspend() calls to the probe failure paths before disabling runtime PM. This issue was found by manual code inspection. Fixes: 78edeb080330 ("clk: imx: scu: add runtime pm support") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li <redacted> --- drivers/clk/imx/clk-scu.c | 4 ++++ 1 file changed, 4 insertions(+)diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c index 9b33df9967ec..6d29fcc2306d 100644 --- a/drivers/clk/imx/clk-scu.c +++ b/drivers/clk/imx/clk-scu.c@@ -542,6 +542,7 @@ static int imx_clk_scu_probe(struct platform_device *pdev)ret = pm_runtime_resume_and_get(dev); if (ret) { pm_genpd_remove_device(dev); + pm_runtime_dont_use_autosuspend(dev); pm_runtime_disable(dev); return ret; }@@ -550,6 +551,9 @@ static int imx_clk_scu_probe(struct platform_device *pdev)hw = __imx_clk_scu(dev, clk->name, clk->parents, clk->num_parents, clk->rsrc, clk->clk_type); if (IS_ERR(hw)) { + if (!(clk->rsrc == IMX_SC_R_A35 || clk->rsrc == IMX_SC_R_A53 || + clk->rsrc == IMX_SC_R_A72)) + pm_runtime_dont_use_autosuspend(dev); pm_runtime_disable(dev); return PTR_ERR(hw);
This is not complete fix. I just write one, see below:
imx_clk_scu_probe() sets up runtime PM for non-CPU clocks by calling
pm_runtime_use_autosuspend(), pm_runtime_enable(), and
pm_runtime_resume_and_get(). The probe failure paths do not properly
undo these operations:
1. When pm_runtime_resume_and_get() fails, pm_runtime_dont_use_autosuspend()
is not called before pm_runtime_disable(), leaving the autosuspend
setting unbalanced.
2. When __imx_clk_scu() fails, pm_runtime_disable() is called
unconditionally even for CPU clocks, which never had pm_runtime_enable()
called, causing an unbalanced disable depth. For non-CPU clocks,
neither pm_runtime_put_noidle() nor pm_runtime_dont_use_autosuspend()
are called, leaving both the usage count and autosuspend setting
unbalanced.
Fix the first path by adding pm_runtime_dont_use_autosuspend() before
pm_runtime_disable(). Fix the second path by guarding all three cleanup
calls — pm_runtime_put_noidle(), pm_runtime_dont_use_autosuspend(), and
pm_runtime_disable() — with the non-CPU clock check.
Fixes: 78edeb080330 ("clk: imx: scu: add runtime pm support")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c
index 9b33df9967ece..63ab4801ddaa7 100644
--- a/drivers/clk/imx/clk-scu.c
+++ b/drivers/clk/imx/clk-scu.c@@ -542,6 +542,7 @@ static int imx_clk_scu_probe(struct platform_device *pdev) ret = pm_runtime_resume_and_get(dev); if (ret) { pm_genpd_remove_device(dev); + pm_runtime_dont_use_autosuspend(dev); pm_runtime_disable(dev); return ret; }
@@ -550,7 +551,12 @@ static int imx_clk_scu_probe(struct platform_device *pdev) hw = __imx_clk_scu(dev, clk->name, clk->parents, clk->num_parents, clk->rsrc, clk->clk_type); if (IS_ERR(hw)) { - pm_runtime_disable(dev); + if (!((clk->rsrc == IMX_SC_R_A35) || (clk->rsrc == IMX_SC_R_A53) || + (clk->rsrc == IMX_SC_R_A72))) { + pm_runtime_put_noidle(dev); + pm_runtime_dont_use_autosuspend(dev); + pm_runtime_disable(dev); + } return PTR_ERR(hw); }
Regards, Peng
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