Re: [v4 2/5] drm/edid: parse multiple CEA extension block

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Mar 02, 2022 at 05:35:08PM +0800, Lee Shawn C wrote:
> Try to find and parse more CEA ext blocks if edid->extensions
> is greater than one.
> 
> v2: split prvious patch to two. And do CEA block parsing
>     in this one.
> v3: simplify this patch based on previous change.
> 
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 36 ++++++++++++++++++++++--------------
>  1 file changed, 22 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 375e70d9de86..c4a47465ba76 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -4319,16 +4319,24 @@ static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
>  static int
>  add_cea_modes(struct drm_connector *connector, struct edid *edid)
>  {
> -	const u8 *cea, *db, *hdmi = NULL, *video = NULL;
> -	u8 dbl, hdmi_len, video_len = 0;
> +	const u8 *cea, *db;
> +	u8 dbl, hdmi_len;
>  	int modes = 0, ext_index = 0;
> +	int i, start, end;

I think everything here apart from modes and ext_index can
be moved into the loop.

Apart from that 1-2 look fine to me. intel-gfx wasn't cc:d however
so we have no ci results for any of this.

>  
> -	cea = drm_find_cea_extension(edid, &ext_index);
> -	if (cea && cea_revision(cea) >= 3) {
> -		int i, start, end;
> +	for (;;) {
> +		const u8 *hdmi = NULL, *video = NULL;
> +		u8 video_len = 0;
> +
> +		cea = drm_find_cea_extension(edid, &ext_index);
> +		if (!cea)
> +			break;
> +
> +		if (cea_revision(cea) < 3)
> +			continue;
>  
>  		if (cea_db_offsets(cea, &start, &end))
> -			return 0;
> +			continue;
>  
>  		for_each_cea_db(cea, i, start, end) {
>  			db = &cea[i];
> @@ -4350,15 +4358,15 @@ add_cea_modes(struct drm_connector *connector, struct edid *edid)
>  							  dbl - 1);
>  			}
>  		}
> -	}
>  
> -	/*
> -	 * We parse the HDMI VSDB after having added the cea modes as we will
> -	 * be patching their flags when the sink supports stereo 3D.
> -	 */
> -	if (hdmi)
> -		modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len, video,
> -					    video_len);
> +		/*
> +		 * We parse the HDMI VSDB after having added the cea modes as we will
> +		 * be patching their flags when the sink supports stereo 3D.
> +		 */
> +		if (hdmi)
> +			modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len, video,
> +						    video_len);
> +	}
>  
>  	return modes;
>  }
> -- 
> 2.17.1

-- 
Ville Syrjälä
Intel