Re: [PATCH v3 03/20] media: imx355: Remove duplicated registers from the mode tables

[sashiko-bot@kernel.org]

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

Pre-existing issues:
- [High] Runtime PM Double Power-Off on probe error path.
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--- Patch [3]: [PATCH v3 03/20] media: imx355: Remove duplicated registers from the mode tables ---
commit 149de34debabe64c5c7c327e825451e79b0feb6c
Author: Dave Stevenson <dave.stevenson@raspberrypi.com>

media: imx355: Remove duplicated registers from the mode tables

A large number of registers are identical within all the modes.
Move those to imx355_global_regs.

> diff --git a/drivers/media/i2c/imx355.c b/drivers/media/i2c/imx355.c
> index ad9a9464175b1..4eaccd9e90f10 100644
> --- a/drivers/media/i2c/imx355.c
> +++ b/drivers/media/i2c/imx355.c
[ ... ]

[Severity: High]
This is a pre-existing issue, but I noticed a potential problem in the
error handling path of imx355_probe():

drivers/media/i2c/imx355.c:imx355_probe() {
    ...
	pm_runtime_set_active(imx355->dev);
	pm_runtime_enable(imx355->dev);
	pm_runtime_idle(imx355->dev);

	ret = v4l2_async_register_subdev_sensor(&imx355->sd);
	if (ret < 0)
		goto error_media_entity_runtime_pm;
    ...
error_media_entity_runtime_pm:
	pm_runtime_disable(imx355->dev);
	pm_runtime_set_suspended(imx355->dev);
	media_entity_cleanup(&imx355->sd.entity);

error_handler_free:
	v4l2_ctrl_handler_free(imx355->sd.ctrl_handler);

error_power_off:
	imx355_power_off(imx355->dev);
    ...
}

Does this code call imx355_power_off() a second time on the error path?

If v4l2_async_register_subdev_sensor() fails, the code jumps to
error_media_entity_runtime_pm. Earlier in the probe, pm_runtime_idle() was
called, which synchronously suspends the device by invoking imx355_power_off().

The error handler then disables runtime PM and falls through to error_power_off,
where it explicitly calls imx355_power_off() again.

Could this double-disabling of regulators and clocks cause reference count
underflows and trigger kernel WARNs (which might panic the system with
panic_on_warn)?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260708-media-imx355-v3-0-9df386a623d7@raspberrypi.com?part=3