[PATCH] drm/edid: request HDMI underscan by default

[Ville Syrjälä]

On Thu, Feb 27, 2014 at 09:19:30AM -0600, Daniel Drake wrote:
> Working with HDMI TVs is a real pain as they tend to overscan by
> default, meaning that the pixels around the edge of the framebuffer
> are not displayed. This is well explained here:
> http://mjg59.dreamwidth.org/8705.html
> 
> There is a bit in the HDMI info frame that can request that the
> remote display shows the full pixel data ("underscan"). For the
> remote display, the HDMI spec states that this is optional - it
> doesn't have to listen. That means that most TVs will probably ignore
> this.
> 
> But, maybe there are a handful of TVs for which this would help
> the situation. As we live in a digital world, ask the remote
> display not to overscan by default.
> 
> Signed-off-by: Daniel Drake <drake at endlessm.com>

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/drm_edid.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> Replaces the patch titled "video: hdmi: request underscan by default"
> This version moves the change to the DRM layer, as requested by
> Ville Syrjälä.
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index b924306..f8d8a1d 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -3599,6 +3599,7 @@ drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
>  
>  	frame->picture_aspect = HDMI_PICTURE_ASPECT_NONE;
>  	frame->active_aspect = HDMI_ACTIVE_ASPECT_PICTURE;
> +	frame->scan_mode = HDMI_SCAN_MODE_UNDERSCAN;
>  
>  	return 0;
>  }
> -- 
> 1.8.3.2

-- 
Ville Syrjälä
Intel OTC