Re: [PATCH v2 5/5] ASoC: rockchip: rockchip_pdm: Handle runtime PM resume failures in set_fmt

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Unbalanced clock disable in `rockchip_pdm_remove` for `pdm->clk` causes an enable count underflow, leading to a kernel warning.
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commit ecd4c53ebd06077db2d8eab0ef6ff0fdc098c863
Author: bui duc phuc <phucduc.bui@gmail.com>

ASoC: rockchip: rockchip_pdm: Handle runtime PM resume failures in set_fmt

This patch replaces pm_runtime_get_sync() with pm_runtime_resume_and_get()
in rockchip_pdm_set_fmt() and adds an early return on failure. This ensures
register accesses are not performed when the device state is undefined.

Reported-by: Sashiko AI Review <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260522110302.349421F000E9@smtp.kernel.org/
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>

> diff --git a/sound/soc/rockchip/rockchip_pdm.c b/sound/soc/rockchip/rockchip_pdm.c
> index 8f78f7bc1806c..115e90d3bbfe0 100644
> --- a/sound/soc/rockchip/rockchip_pdm.c
> +++ b/sound/soc/rockchip/rockchip_pdm.c

[ ... ]

> static void rockchip_pdm_remove(struct platform_device *pdev)
> {
> 	struct rk_pdm_dev *pdm = dev_get_drvdata(&pdev->dev);
> 
> 	pm_runtime_disable(&pdev->dev);
> 	if (!pm_runtime_status_suspended(&pdev->dev))
> 		rockchip_pdm_runtime_suspend(&pdev->dev);
> 
> 	clk_disable_unprepare(pdm->clk);

[Severity: High]
This is a pre-existing issue, but does this unconditional disable cause an
enable count underflow for pdm->clk?

In rockchip_pdm_probe(), pdm->clk is acquired but not enabled. It appears to
only be enabled dynamically via rockchip_pdm_runtime_resume(). During
rockchip_pdm_remove(), the driver correctly calls rockchip_pdm_runtime_suspend()
if the device is active, which disables the clock and drops its reference count
to 0.

However, calling clk_disable_unprepare() again immediately after would push
the reference count below zero, triggering a Common Clock Framework warning
in clk_core_disable(). Could this be repeatedly triggered via sysfs driver
unbind to cause a denial of service if panic_on_warn is set?

> 	clk_disable_unprepare(pdm->hclk);
> }

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Sashiko AI review · https://sashiko.dev/#/patchset/20260602101608.45137-1-phucduc.bui@gmail.com?part=5