On Mon, Jan 24, 2022 at 5:16 PM Daniel Vetter <[email protected]> wrote: > > 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). > > Cc: Laurent Pinchart <[email protected]> > Reviewed-by: Laurent Pinchart <[email protected]> > Cc: Geert Uytterhoeven <[email protected]> > Cc: Ville Syrjälä <[email protected]> > Cc: Maarten Lankhorst <[email protected]> > Cc: Maxime Ripard <[email protected]> > Cc: Thomas Zimmermann <[email protected]> > Cc: David Airlie <[email protected]> > Cc: Daniel Vetter <[email protected]> > Signed-off-by: Daniel Vetter <[email protected]>
Reviewed-by: Alex Deucher <[email protected]> > --- > drivers/gpu/drm/drm_color_mgmt.c | 4 ++++ > include/drm/drm_crtc.h | 10 ++++++++++ > 2 files changed, 14 insertions(+) > > 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). > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > index 4d01b4d89775..a70baea0636c 100644 > --- a/include/drm/drm_crtc.h > +++ b/include/drm/drm_crtc.h > @@ -285,6 +285,10 @@ struct drm_crtc_state { > * Lookup table for converting pixel data after the color conversion > * matrix @ctm. See drm_crtc_enable_color_mgmt(). The blob (if not > * NULL) is an array of &struct drm_color_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. > */ > struct drm_property_blob *gamma_lut; > > @@ -1075,12 +1079,18 @@ struct drm_crtc { > /** > * @gamma_size: Size of legacy gamma ramp reported to userspace. Set > up > * by calling drm_mode_crtc_set_gamma_size(). > + * > + * Note that atomic drivers need to instead use > + * &drm_crtc_state.gamma_lut. See drm_crtc_enable_color_mgmt(). > */ > uint32_t gamma_size; > > /** > * @gamma_store: Gamma ramp values used by the legacy SETGAMMA and > * GETGAMMA IOCTls. Set up by calling drm_mode_crtc_set_gamma_size(). > + * > + * Note that atomic drivers need to instead use > + * &drm_crtc_state.gamma_lut. See drm_crtc_enable_color_mgmt(). > */ > uint16_t *gamma_store; > > -- > 2.33.0 >
