The DRM core handles legacy gamma-set ioctl by setting GAMMA_LUT and clearing CTM and DEGAMMA_LUT.
This works fine on HW where we have either:
degamma -> ctm -> gamma -> out
or
ctm -> gamma -> out
However, if the HW has gamma table before ctm, the atomic property should be DEGAMMA_LUT, and thus we have:
degamma -> ctm -> out
This is fine for userspace which sets gamma table using the properties, as the userspace can check for the existence of gamma & degamma, but the legacy gamma-set ioctl does not work.
Change the DRM core to use DEGAMMA_LUT instead of GAMMA_LUT when the latter is unavailable.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com --- drivers/gpu/drm/drm_color_mgmt.c | 22 ++++++++++++++++++---- drivers/gpu/drm/drm_fb_helper.c | 5 +++++ 2 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index 65eb36dc92bf..9100aac1570c 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -91,7 +91,7 @@ * * There is also support for a legacy gamma table, which is set up by calling * drm_mode_crtc_set_gamma_size(). The DRM core will then alias the legacy gamma - * ramp with "GAMMA_LUT". + * ramp with "GAMMA_LUT" or, if that is unavailable, "DEGAMMA_LUT". * * Support for different non RGB color encodings is controlled through * &drm_plane specific COLOR_ENCODING and COLOR_RANGE properties. They @@ -238,6 +238,7 @@ EXPORT_SYMBOL(drm_mode_crtc_set_gamma_size); static bool drm_crtc_supports_legacy_gamma(struct drm_crtc *crtc) { uint32_t gamma_id = crtc->dev->mode_config.gamma_lut_property->base.id; + uint32_t degamma_id = crtc->dev->mode_config.degamma_lut_property->base.id;
if (!crtc->gamma_size) return false; @@ -245,7 +246,8 @@ static bool drm_crtc_supports_legacy_gamma(struct drm_crtc *crtc) if (crtc->funcs->gamma_set) return true;
- return !!drm_mode_obj_find_prop_id(&crtc->base, gamma_id); + return !!(drm_mode_obj_find_prop_id(&crtc->base, gamma_id) || + drm_mode_obj_find_prop_id(&crtc->base, degamma_id)); }
/** @@ -276,12 +278,22 @@ static int drm_crtc_legacy_gamma_set(struct drm_crtc *crtc, struct drm_crtc_state *crtc_state; struct drm_property_blob *blob; struct drm_color_lut *blob_data; + uint32_t gamma_id = dev->mode_config.gamma_lut_property->base.id; + uint32_t degamma_id = dev->mode_config.degamma_lut_property->base.id; + bool use_gamma_lut; int i, ret = 0; bool replaced;
if (crtc->funcs->gamma_set) return crtc->funcs->gamma_set(crtc, red, green, blue, size, ctx);
+ if (drm_mode_obj_find_prop_id(&crtc->base, gamma_id)) + use_gamma_lut = true; + else if (drm_mode_obj_find_prop_id(&crtc->base, degamma_id)) + use_gamma_lut = false; + else + return -ENODEV; + state = drm_atomic_state_alloc(crtc->dev); if (!state) return -ENOMEM; @@ -311,9 +323,11 @@ static int drm_crtc_legacy_gamma_set(struct drm_crtc *crtc, }
/* Set GAMMA_LUT and reset DEGAMMA_LUT and CTM */ - replaced = drm_property_replace_blob(&crtc_state->degamma_lut, NULL); + replaced = drm_property_replace_blob(&crtc_state->degamma_lut, + use_gamma_lut ? NULL : blob); replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL); - replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob); + replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, + use_gamma_lut ? blob : NULL); crtc_state->color_mgmt_changed |= replaced;
ret = drm_atomic_commit(state); diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index e82db0f4e771..5ad19785daee 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1059,6 +1059,11 @@ static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info) goto out_state; }
+ /* + * FIXME: This always uses gamma_lut. Some HW have only + * degamma_lut, in which case we should reset gamma_lut and set + * degamma_lut. See drm_crtc_legacy_gamma_set(). + */ replaced = drm_property_replace_blob(&crtc_state->degamma_lut, NULL); replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);