[PATCH RESEND] drm/rockchip: cdn-dp: add missing check in cdn_dp_config_video()

[Chaoyi Chen]

On 1/31/2026 4:35 AM, Sergey Shtylyov wrote:
> The result of cdn_dp_reg_write() is checked everywhere (with the error
> being logged by the callers) except one place in cdn_dp_config_video().
> Add the missing result check, bailing out early on error...
> 
> Found by Linux Verification Center (linuxtesting.org) with the Svace static
> analysis tool.
> 
> Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for rk3399")
> Signed-off-by: Sergey Shtylyov <s.shtylyov at auroraos.dev>
> Cc: stable at vger.kernel.org
> ---
> Either we need to add the check or drop the assignment to the ret variable
> as the value gets ignored anyway...
> 
> The patch is against the drm-misc-fixes branch of the DRM kernel.git repo
> on gitlab.freedesktop.org.
> 
>  drivers/gpu/drm/rockchip/cdn-dp-reg.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
> index 0dc3804051a9..9b82b27770e5 100644
> --- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c
> +++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
> @@ -685,6 +685,8 @@ int cdn_dp_config_video(struct cdn_dp_device *dp)
>  	val = div_u64(8 * (symbol + 1), bit_per_pix) - val;
>  	val += 2;
>  	ret = cdn_dp_reg_write(dp, DP_VC_TABLE(15), val);
> +	if (ret)
> +		goto err_config_video;
>  
>  	switch (video->color_depth) {
>  	case 6:

Not sure why this was resent, but it looks good to me :)

Reviewed-by: Chaoyi Chen <chaoyi.chen at rock-chips.com>

-- 
Best, 
Chaoyi