Re: [PATCH v4 02/14] drm/bridge: analogix_dp: Check all negative return values for &analogix_dp_device.irq

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] drm/bridge: analogix_dp: unsigned dp->irq < 0 check in analogix_dp_probe()
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commit fcbed20d54db2072c70e2845510fbc672a7f0240
Author: Damon Ding <damon.ding@rock-chips.com>

drm/bridge: analogix_dp: Check all negative return values for &analogix_dp_device.irq

This commit updates analogix_dp_probe() to check for any negative return
value in dp->irq rather than only -ENXIO, and propagates the error code
instead of returning -ENODEV.

Link: https://lore.kernel.org/all/20260804083307.84ECA1F000E9@smtp.kernel.org/

> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index 079f2f01f33b0..27c9a764e25fa 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -1480,9 +1480,9 @@ analogix_dp_probe(struct device *dev, struct analogix_dp_plat_data *plat_data)
>  		irq_flags = IRQF_NO_AUTOEN;
>  	}
>  
> -	if (dp->irq == -ENXIO) {
> +	if (dp->irq < 0) {
>  		dev_err(&pdev->dev, "failed to get irq\n");
> -		return ERR_PTR(-ENODEV);
> +		return ERR_PTR(dp->irq);
>  	}
>  
>  	ret = devm_request_threaded_irq(&pdev->dev, dp->irq,

[Severity: High]
Can dp->irq < 0 ever be true here? In struct analogix_dp_device in
drivers/gpu/drm/bridge/analogix/analogix_dp_core.h, irq is declared as
unsigned int:

struct analogix_dp_device {
	...
	struct clk		*clock;
	unsigned int		irq;
	void __iomem		*reg_base;

When gpiod_to_irq() or platform_get_irq() returns a negative error code
(such as -EPROBE_DEFER, -ENOENT, or -ENXIO) in analogix_dp_probe(), the
value is stored in the unsigned dp->irq field.

Because dp->irq is unsigned, the dp->irq < 0 comparison is always false.
All negative error codes bypass this check and are passed as large
unsigned values to devm_request_threaded_irq(), which fails with -EINVAL
instead of propagating the original error code (breaking probe deferral).
Additionally, on 64-bit systems, passing an unsigned int to ERR_PTR()
zero-extends it to long rather than sign-extending it.

Would it make sense to change irq to int in struct analogix_dp_device, or
assign the return value of gpiod_to_irq() and platform_get_irq() to ret
first and check ret < 0 before storing it in dp->irq?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261019085836.3065008-1-damon.ding@rock-chips.com?part=2