Re: [PATCH] drm/amd/display: Fix error returned by program_hpd_filter

[Harry Wentland]

On 2019-11-17 12:22 p.m., Aditya Pakki wrote:
> program_hpd_filter() currently fails to check for the errors
> returned in construct(). This patch returns error in
> case of failure.
> 
> Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
> ---
>  drivers/gpu/drm/amd/display/dc/core/dc_link.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
> index ca20b150afcc..bbb648a50c41 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
> @@ -1379,9 +1379,8 @@ static bool construct(
>  	 * If GPIO isn't programmed correctly HPD might not rise or drain
>  	 * fast enough, leading to bounces.
>  	 */
> -	program_hpd_filter(link);
> +	return program_hpd_filter(link);

We don't want program_hpd_filter to become a fatal error, which this
would do.

Though it would be good to print a warning if program_hpd_filter fails
as it's unexpected and might lead to bugs with some displays. In many
cases failing to program the HPD filter won't lead to adverse behavior.

Harry

>  
> -	return true;
>  device_tag_fail:
>  	link->link_enc->funcs->destroy(&link->link_enc);
>  link_enc_create_fail:
>