On Tue, Jan 20, 2026 at 11:37:59AM -0500, [email protected] wrote: > > > > On Jan 20, 2026, at 10:41 AM, Ville Syrjälä <[email protected]> > > wrote: > > > > On Mon, Jan 19, 2026 at 03:39:12PM +0200, Jani Nikula wrote: > >> On Sat, 17 Jan 2026, Joshua Peisach <[email protected]> wrote: > >>> drm_parse_hdmi_vsdb_video is one of the parsers that still do not use the > >>> cea_db struct, and currently passes a u8 pointer. > >>> > >>> Set the correct struct type and update references to the data accordingly. > >>> This also makes the same change to drm_parse_hdmi_deep_color_info as > >>> necessary. > >>> > >>> Signed-off-by: Joshua Peisach <[email protected]> > >>> --- > >>> drivers/gpu/drm/drm_edid.c | 26 +++++++++++++------------- > >>> 1 file changed, 13 insertions(+), 13 deletions(-) > >>> > >>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > >>> index 26bb7710a..15bd99e65 100644 > >>> --- a/drivers/gpu/drm/drm_edid.c > >>> +++ b/drivers/gpu/drm/drm_edid.c > >>> @@ -6290,7 +6290,7 @@ static void drm_parse_hdmi_forum_scds(struct > >>> drm_connector *connector, > >>> } > >>> > >>> static void drm_parse_hdmi_deep_color_info(struct drm_connector > >>> *connector, > >>> - const u8 *hdmi) > >>> + const struct cea_db *db) > >>> { > >>> struct drm_display_info *info = &connector->display_info; > >>> unsigned int dc_bpc = 0; > >>> @@ -6298,24 +6298,24 @@ static void drm_parse_hdmi_deep_color_info(struct > >>> drm_connector *connector, > >>> /* HDMI supports at least 8 bpc */ > >>> info->bpc = 8; > >>> > >>> - if (cea_db_payload_len(hdmi) < 6) > >>> + if (cea_db_payload_len(db) < 6) > >>> return; > >>> > >>> - if (hdmi[6] & DRM_EDID_HDMI_DC_30) { > >>> + if (db->data[6] & DRM_EDID_HDMI_DC_30) { > >> > >> That's not the same thing, but off-by-one now. Ditto everywhere that > >> changes from u8* to db->data[]. > >> > >> The main problem with the change (even with fixed offsets) is that the > >> *specs* typically use indexing from the beginning of the data block, not > >> from the beginning of payload data. > >> > >> We've discussed this before with Ville (Cc'd) but I'm not sure if we > >> reached a conclusion. > > > > I guess we could give up on the index matching the spec byte#. > > Looks like the HDMI VSDB parsing is the only place where we > > actually have the two match, and everwhere else it's > > already inconsistent. > > > > Also maybe we should add something to also exclude the > > extended tag from the payload, for the blocks that use > > the extended tag... > > > > -- > > Ville Syrjälä > > Intel > > I personally believe it is important to match the spec for consistency > and reference. Unless I am looking at the wrong thing, bit 6 should have > the correct index. > > Also I think cea_db in the context of the function calls here are > just the data blocks. Unless you mean that by having the struct's first > member being the tag_length if offsetting everything, but I don't think > it is? Let me know if I'm wrong :)
The tag+length byte is: byte# 1 in the CTA spec byte# 0 in the HDMI spec There's no super nice way to use the byte# as the index for both. Also the length checks end up looking somewhat confusing when comparing them with the corresponding index. -- Ville Syrjälä Intel
