[PATCH] drm/mediatek/dp: fix mtk_dp_aux_transfer return value

[CK Hu (胡俊光)]

Hi, Wojciech:

On Tue, 2024-04-02 at 07:11 +0000, Wojciech Macek wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  From: Wojciech Macek <wmacek at chromium.com>
> 
> In case there is no DP device attached to the port the
> transfer function should return IO error, similar to what
> other drivers do.
> In case EAGAIN is returned then any read from /dev/drm_dp_aux
> device ends up in an infinite loop as the upper layers
> constantly repeats the transfer request.

This patch looks good to me, but need fixes tag, please refer to [1] to
add fixes tag.

[1] 
https://www.kernel.org/doc/html/v6.8/process/submitting-patches.html

Regards,
CK

> 
> Signed-off-by: Wojciech Macek <wmacek at chromium.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c
> b/drivers/gpu/drm/mediatek/mtk_dp.c
> index 0ba72102636a..536366956447 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> @@ -2104,7 +2104,7 @@ static ssize_t mtk_dp_aux_transfer(struct
> drm_dp_aux *mtk_aux,
>  
>  	if (mtk_dp->bridge.type != DRM_MODE_CONNECTOR_eDP &&
>  	    !mtk_dp->train_info.cable_plugged_in) {
> -		ret = -EAGAIN;
> +		ret = -EIO;
>  		goto err;
>  	}
>  
> -- 
> 2.44.0.478.gd926399ef9-goog
>