[PATCH 4/4] drm/edid: Prep for HDMI VIC aspect ratio (WIP)

[Lin, Wayne]

> -----Original Message-----
> From: Ville Syrjala <ville.syrjala at linux.intel.com>
> Sent: Friday, October 4, 2019 10:19 PM
> To: dri-devel at lists.freedesktop.org
> Cc: intel-gfx at lists.freedesktop.org; Lin, Wayne <Wayne.Lin at amd.com>
> Subject: [PATCH 4/4] drm/edid: Prep for HDMI VIC aspect ratio (WIP)
> 
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> I think this should provide most of necessary logic for adding aspecr ratios to
> the HDMI 4k modes.
> 
> Cc: Wayne Lin <waynelin at amd.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 37 +++++++++++++++++++++++++++++++------
>  1 file changed, 31 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index
> c7f9f7ca75a2..c76814edc784 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -3210,6 +3210,11 @@ static enum hdmi_picture_aspect
> drm_get_cea_aspect_ratio(const u8 video_code)
>  	return edid_cea_modes[video_code].picture_aspect_ratio;
>  }
> 
> +static enum hdmi_picture_aspect drm_get_hdmi_aspect_ratio(const u8
> +video_code) {
> +	return edid_4k_modes[video_code].picture_aspect_ratio;
> +}
> +

There are no picture_aspect_ratio attributes defined for modes in 
edid_4k_modes[] now. Should add on those definitions.

>  /*
>   * Calculate the alternate clock for HDMI modes (those from the HDMI
> vendor
>   * specific block).
> @@ -3236,6 +3241,9 @@ static u8
> drm_match_hdmi_mode_clock_tolerance(const struct drm_display_mode *to_
>  	if (!to_match->clock)
>  		return 0;
> 
> +	if (to_match->picture_aspect_ratio)
> +		match_flags |= DRM_MODE_MATCH_ASPECT_RATIO;
> +
>  	for (vic = 1; vic < ARRAY_SIZE(edid_4k_modes); vic++) {
>  		const struct drm_display_mode *hdmi_mode =
> &edid_4k_modes[vic];
>  		unsigned int clock1, clock2;
> @@ -3271,6 +3279,9 @@ static u8 drm_match_hdmi_mode(const struct
> drm_display_mode *to_match)
>  	if (!to_match->clock)
>  		return 0;
> 
> +	if (to_match->picture_aspect_ratio)
> +		match_flags |= DRM_MODE_MATCH_ASPECT_RATIO;
> +
>  	for (vic = 1; vic < ARRAY_SIZE(edid_4k_modes); vic++) {
>  		const struct drm_display_mode *hdmi_mode =
> &edid_4k_modes[vic];
>  		unsigned int clock1, clock2;

Current code in drm_match_hdmi_mdoe() & drm_match_hdmi_mode_clock_tolerance()
use hdmi_mode_alternate_clock() to find alternate clocks.
In hdmi_mode_alternate_clock(), it adds an exception for VIC 4 mode (4096x2160 at 24)
due to there is no alternate clock defined for that mode in HDMI1.4b. But HDMI2.0 adds
23.98Hz for that mode. Maybe we should also revise that part.

> @@ -5218,6 +5229,7 @@
> drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe
> *frame,
>  					 const struct drm_display_mode *mode)  {
>  	enum hdmi_picture_aspect picture_aspect;
> +	u8 vic, hdmi_vic;
>  	int err;
> 
>  	if (!frame || !mode)
> @@ -5230,7 +5242,8 @@
> drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe
> *frame,
>  	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
>  		frame->pixel_repeat = 1;
> 
> -	frame->video_code = drm_mode_cea_vic(connector, mode);
> +	vic = drm_mode_cea_vic(connector, mode);
> +	hdmi_vic = drm_mode_hdmi_vic(connector, mode);
> 
>  	frame->picture_aspect = HDMI_PICTURE_ASPECT_NONE;
> 
> @@ -5244,11 +5257,15 @@
> drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe
> *frame,
> 
>  	/*
>  	 * Populate picture aspect ratio from either
> -	 * user input (if specified) or from the CEA mode list.
> +	 * user input (if specified) or from the CEA/HDMI mode lists.
>  	 */
>  	picture_aspect = mode->picture_aspect_ratio;
> -	if (picture_aspect == HDMI_PICTURE_ASPECT_NONE)
> -		picture_aspect = drm_get_cea_aspect_ratio(frame->video_code);
> +	if (picture_aspect == HDMI_PICTURE_ASPECT_NONE) {
> +		if (vic)
> +			picture_aspect = drm_get_cea_aspect_ratio(vic);
> +		else if (hdmi_vic)
> +			picture_aspect = drm_get_hdmi_aspect_ratio(hdmi_vic);
> +	}
> 
>  	/*
>  	 * The infoframe can't convey anything but none, 4:3 @@ -5256,12
> +5273,20 @@ drm_hdmi_avi_infoframe_from_display_mode(struct
> hdmi_avi_infoframe *frame,
>  	 * we can only satisfy it by specifying the right VIC.
>  	 */
>  	if (picture_aspect > HDMI_PICTURE_ASPECT_16_9) {
> -		if (picture_aspect !=
> -		    drm_get_cea_aspect_ratio(frame->video_code))
> +		if (vic) {
> +			if (picture_aspect != drm_get_cea_aspect_ratio(vic))
> +				return -EINVAL;
> +		} else if (hdmi_vic) {
> +			if (picture_aspect != drm_get_hdmi_aspect_ratio(hdmi_vic))
> +				return -EINVAL;
> +		} else {
>  			return -EINVAL;
> +		}
> +
>  		picture_aspect = HDMI_PICTURE_ASPECT_NONE;
>  	}
> 
> +	frame->video_code = vic;
>  	frame->picture_aspect = picture_aspect;
>  	frame->active_aspect = HDMI_ACTIVE_ASPECT_PICTURE;
>  	frame->scan_mode = HDMI_SCAN_MODE_UNDERSCAN;
> --
> 2.21.0

--
Wayne Lin