Re: [PATCH] drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] drm/sun4i: misapplied patch causes build failure
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commit 576ab0ea69ae3e401d6153bcb00f1e660850ae75
Author: Wentao Liang <vulab@iscas.ac.cn>

drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux()

This commit attempts to fix a claimed reference leak in the success path of
sun8i_r40_tcon_tv_set_mux(). However, the patch modifies the wrong function
and introduces a build failure.

Fixes: 0305189afb32 ("drm/sun4i: tcon: Add support for R40 TCON")
Cc: stable@vger.kernel.org

> drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux()
> 
> of_find_device_by_node() takes a reference to the TCON TOP device
> which the error paths release, but the success path returns without
> doing so.  Drop the reference before returning success.

The commit message states it fixes a leak in sun8i_r40_tcon_tv_set_mux(),
but the patch actually modifies sun4i_tcon_init_clocks().

Looking at sun8i_r40_tcon_tv_set_mux() in the baseline, the success path
appears to fall through to the out_put_device label, which already correctly
drops the reference:

out_put_device:
        put_device(&pdev->dev);

        return ret;

Could the commit message be referencing an issue that does not exist in
this tree, or was the patch misapplied?

> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index bf405a2aa3249..b5a85738876ee 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -808,6 +808,8 @@ static int sun4i_tcon_init_clocks(struct device *dev,
>  		}
>  	}
>  
> +	put_device(&pdev->dev);

[Severity: Low]
Does this code compile? The variable pdev is undeclared in the scope of
sun4i_tcon_init_clocks(), which causes a build failure.

> +
>  	return 0;
>  }

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Sashiko AI review · https://sashiko.dev/#/patchset/20260916182412.2091681-1-vulab@iscas.ac.cn?part=1