> 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 :)
-Josh
