-----Original Message----- From: Intel-gfx intel-gfx-bounces@lists.freedesktop.org On Behalf Of Ville Syrjala Sent: Saturday, January 25, 2020 1:32 AM To: dri-devel@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org; Andres Rodriguez andresx7@gmail.com Subject: [Intel-gfx] [PATCH 6/8] drm/edid: Add a FIXME about DispID CEA data block revision
From: Ville Syrjälä ville.syrjala@linux.intel.com
I don't understand what the DispID CEA data block revision means. The spec doesn't say. I guess some DispID must have a value of >= 3 in there or else we generally wouldn't even parse the CEA data blocks. Or does all this code actually not do anything?
This signifies the CTA extension revision (byte 1 of the block). As per the spec, seems like Version 1 is legacy and 2 is deprecated. So version >=3 is checked here. Refer section 7.3 of CTA-861-G
Cc: Andres Rodriguez andresx7@gmail.com Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
drivers/gpu/drm/drm_edid.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 0369a54e3d32..fd9b724067a7 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -3977,6 +3977,13 @@ cea_db_tag(const u8 *db) static int cea_revision(const u8 *cea) {
- /*
* FIXME is this correct for the DispID variant?* The DispID spec doesn't really specify whether* this is the revision of the CEA extension or* the DispID CEA data block. And the only value* given as an example is 0.*/}
-- 2.24.1
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