[Intel-gfx] [PATCH v3] drm/edid: detect color formats and CTA revision in all CTA extensions

[Jani Nikula <jani.nikula@intel.com>]

Convert drm_find_cea_extension() to EDID block iterator in color format
and CTA revision detection. Detect them in all CTA extensions.

Also parse CTA Data Blocks in DisplayID even if there's no CTA EDID
extension.

v2:
- Don't assume DRM_COLOR_FORMAT_RGB444 support if there's only DisplayID
  CTA Data Blocks (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 3b18a6e501df..8d737322145c 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5447,26 +5447,31 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 			      const struct edid *edid)
 {
 	struct drm_display_info *info = &connector->display_info;
+	struct drm_edid_iter edid_iter;
 	const struct cea_db *db;
 	struct cea_db_iter iter;
 	const u8 *edid_ext;
 
-	edid_ext = drm_find_cea_extension(edid);
-	if (!edid_ext)
-		return;
+	drm_edid_iter_begin(edid, &edid_iter);
+	drm_edid_iter_for_each(edid_ext, &edid_iter) {
+		if (edid_ext[0] != CEA_EXT)
+			continue;
 
-	info->cea_rev = edid_ext[1];
+		if (!info->cea_rev)
+			info->cea_rev = edid_ext[1];
 
-	/* The existence of a CEA block should imply RGB support */
-	info->color_formats = DRM_COLOR_FORMAT_RGB444;
+		if (info->cea_rev != edid_ext[1])
+			DRM_DEBUG_KMS("CEA extension version mismatch %u != %u\n",
+				      info->cea_rev, edid_ext[1]);
 
-	/* CTA DisplayID Data Block does not have byte #3 */
-	if (edid_ext[0] == CEA_EXT) {
+		/* The existence of a CTA extension should imply RGB support */
+		info->color_formats = DRM_COLOR_FORMAT_RGB444;
 		if (edid_ext[3] & EDID_CEA_YCRCB444)
 			info->color_formats |= DRM_COLOR_FORMAT_YCBCR444;
 		if (edid_ext[3] & EDID_CEA_YCRCB422)
 			info->color_formats |= DRM_COLOR_FORMAT_YCBCR422;
 	}
+	drm_edid_iter_end(&edid_iter);
 
 	cea_db_iter_edid_begin(edid, &iter);
 	cea_db_iter_for_each(db, &iter) {
-- 
2.30.2