drm/edid: Reshuffle mode list construction to closer match the spec

Also, document what the spec says to do.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 9c4717ff5f71..858fedc33d9b 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1377,10 +1377,24 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
 
         quirks = edid_get_quirks(edid);
 
-        num_modes += add_established_modes(connector, edid);
-        num_modes += add_standard_modes(connector, edid);
+        /*
+         * EDID spec says modes should be preferred in this order:
+         * - preferred detailed mode
+         * - other detailed modes from base block
+         * - detailed modes from extension blocks
+         * - CVT 3-byte code modes
+         * - standard timing codes
+         * - established timing codes
+         * - modes inferred from GTF or CVT range information
+         *
+         * We don't quite implement this yet, but we're close.
+         *
+         * XXX order for additional mode types in extension blocks?
+         */
         num_modes += add_detailed_info(connector, edid, quirks);
         num_modes += add_detailed_info_eedid(connector, edid, quirks);
+        num_modes += add_standard_modes(connector, edid);
+        num_modes += add_established_modes(connector, edid);
 
         if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
                 edid_fixup_preferred(connector, quirks);