RE: [PATCH v2] drm/edid: ignore the CEA modes not defined in CEA-861-D

["Tseng, William" <william.tseng@intel.com>]

Thanks Wayne for clarifying.
I will correct the typos and submit the patch again.


-----Original Message-----
From: Lin, Wayne <Wayne.Lin@amd.com> 
Sent: Monday, June 13, 2022 3:25 PM
To: Tseng, William <william.tseng@intel.com>; dri-devel@lists.freedesktop.org
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>; Jani Nikula <jani.nikula@linux.intel.com>; Lee, Shawn C <shawn.c.lee@intel.com>
Subject: RE: [PATCH v2] drm/edid: ignore the CEA modes not defined in CEA-861-D

[AMD Official Use Only - General]

Thanks William!

After fixing few typos below, feel free to add:

Acked-by: Wayne Lin <Wayne.Lin@amd.com>

> -----Original Message-----
> From: William Tseng <william.tseng@intel.com>
> Sent: Monday, June 13, 2022 12:27 PM
> To: dri-devel@lists.freedesktop.org
> Cc: William Tseng <william.tseng@intel.com>; Ville Syrjälä 
> <ville.syrjala@linux.intel.com>; Jani Nikula 
> <jani.nikula@linux.intel.com>; Lin, Wayne <Wayne.Lin@amd.com>; Lee 
> Shawn C <shawn.c.lee@intel.com>
> Subject: [PATCH v2] drm/edid: ignore the CEA modes not defined in CEA- 
> 861-D
> 
> This is a workaround for HDMI 1.4 sink which has a CEA mode with 
> higher vic than what is defined in CEA-861-D.
> 
> As an example, a HDMI 1.4 sink has the video format 2560x1080p to be 
> displayed and the video format is indicated by both SVD (with vic 90 
> and pictuure aspect ratio 64:27) and DTD.  When connecting to such 
> sink, source

Typo - picture
> can't output the video format in SVD because an error is returned by 
> drm_hdmi_avi_infoframe_from_display_mode(), which can't fill the 
> infoframe with pictuure aspect ratio 64:27 and the vic, which is 
> originally 90

Typo - picture
> and is changed to 0 by drm_mode_cea_vic().
> 
> To work around it, do not set the vic 0 so the corresponding mode may 
> be accepted in drm_hdmi_avi_infoframe_from_display_mode() and be 
> dispalyed.
> 
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Wayne Lin <waynelin@amd.com>
> Cc: Lee Shawn C <shawn.c.lee@intel.com>
> Signed-off-by: William Tseng <william.tseng@intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c 
> index bc43e1b32092..a4582627ec9d 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -5876,7 +5876,8 @@ static u8 drm_mode_hdmi_vic(const struct 
> drm_connector *connector,  }
> 
>  static u8 drm_mode_cea_vic(const struct drm_connector *connector,
> -			   const struct drm_display_mode *mode)
> +			   const struct drm_display_mode *mode,
> +			   bool is_hdmi2_sink)
>  {
>  	u8 vic;
> 
> @@ -5896,7 +5897,7 @@ static u8 drm_mode_cea_vic(const struct 
> drm_connector *connector,
>  	 * HDMI 2.0 VIC range: 1 <= VIC <= 107 (CEA-861-F). So we
>  	 * have to make sure we dont break HDMI 1.4 sinks.
>  	 */
> -	if (!is_hdmi2_sink(connector) && vic > 64)
> +	if (!is_hdmi2_sink && vic > 64)
>  		return 0;
> 
>  	return vic;
> @@ -5927,7 +5928,7 @@
> drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe 
> *frame,
>  	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
>  		frame->pixel_repeat = 1;
> 
> -	vic = drm_mode_cea_vic(connector, mode);
> +	vic = drm_mode_cea_vic(connector, mode, true);
>  	hdmi_vic = drm_mode_hdmi_vic(connector, mode);
> 
>  	frame->picture_aspect = HDMI_PICTURE_ASPECT_NONE; @@ -
> 5971,7 +5972,8 @@ drm_hdmi_avi_infoframe_from_display_mode(struct
> hdmi_avi_infoframe *frame,
>  		picture_aspect = HDMI_PICTURE_ASPECT_NONE;
>  	}
> 
> -	frame->video_code = vic;
> +	frame->video_code = drm_mode_cea_vic(connector, mode,
> +						is_hdmi2_sink(connector));
>  	frame->picture_aspect = picture_aspect;
>  	frame->active_aspect = HDMI_ACTIVE_ASPECT_PICTURE;
>  	frame->scan_mode = HDMI_SCAN_MODE_UNDERSCAN;
> --
> 2.17.1