diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2022-01-24 23:16:33 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2022-01-25 09:36:20 +0100 |
| commit | 4fd5e720b709b87f67809a871fde9fb6cb910f28 (patch) | |
| tree | d71db39296e4770637771b6ef23d7bfadf38b389 /drivers | |
| parent | 8b250cd3b5da18bd90f34ecb04c01661213b65ba (diff) | |
drm/docs: Document where the C8 color lut is stored
Also add notes that for atomic drivers it's really somewhere else and
no longer in struct drm_crtc.
Maybe we should put a bigger warning here that this is confusing,
since the pixel format is a plane property, but the GAMMA_LUT property
is on the crtc. But I think we can fix this if/when someone finds a
need for a per-plane CLUT, since I'm not sure such hw even exists. I'm
also not sure whether even hardware with a CLUT and a full color
correction pipeline with degamm/cgm/gamma exists.
Motivated by comments from Geert that we have a gap here.
v2: More names for color luts (Laurent).
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220124221633.952374-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/drm_color_mgmt.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index bb14f488c8f6..9079fbe21d2f 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -82,6 +82,10 @@ * driver boot-up state too. Drivers can access this blob through * &drm_crtc_state.gamma_lut. * + * Note that for mostly historical reasons stemming from Xorg heritage, + * this is also used to store the color map (also sometimes color lut, CLUT + * or color palette) for indexed formats like DRM_FORMAT_C8. + * * “GAMMA_LUT_SIZE”: * Unsigned range property to give the size of the lookup table to be set * on the GAMMA_LUT property (the size depends on the underlying hardware). |