From 1b8977434606f2dcd8a90ca660eb535b56945662 Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Fri, 11 Dec 2020 13:42:37 +0200 Subject: [PATCH] drm: add legacy support for using degamma for gamma 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 Reviewed-by: Laurent Pinchart Link: https://patchwork.freedesktop.org/patch/msgid/20201211114237.213288-3-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 553f423..bb14f48 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) { u32 gamma_id = crtc->dev->mode_config.gamma_lut_property->base.id; + u32 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; + u32 gamma_id = dev->mode_config.gamma_lut_property->base.id; + u32 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 e82db0f..5ad1978 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1059,6 +1059,11 @@ retry: 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); -- 2.7.4