[PATCH v3] drm: Fix crtc color management when doing suspend/resume

[Alexandru Gheorghe]

When doing suspend/resume drivers usually use the
drm_atomic_helper_suspend/drm_atomic_helper_resume pair for saving the
state and then re-comitting it.

The problem is that drm_crtc_state has a bool field called
color_mgmt_changed, which mali-dp and other drivers uses it to detect
if coefficients need to be reprogrammed, but that never happens
because the saved state has color_mgmt_changed set to 0.

Fix that by setting color_mgmt_changed to true in
drm_atomic_helper_check_modeset when at least one of gamma_lut,
degamma_lut, ctm is different between the new and the old crtc state.

All current drivers that use color_mgmt_changed, either call directly
drm_atomic_helper_check_modeset or they use drm_atomic_helper_check
which calls drm_atomic_helper_check_modeset, so this makes unnecessary
the setting of color_mgmt_changed in places where
gamma_lut/degamma_lut/ctm are set in the new crtc_state.

Changes since v2:
  - Instead of setting color_mgmt_changed in commit_duplicated_set
    just set it in check_modeset and clean up other place where it was
    set, suggested by Maarten Lankhorst.

Changes since v3:
  - Rebased v2 on top of drm-misc-next and fix conflicts introduced by
    the move of drm_atomic_crtc_set_property in drm_atomic_uapi.c.

Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe at arm.com>
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_atomic_helper.c |  8 +++++++-
 drivers/gpu/drm/drm_atomic_uapi.c   | 12 +++---------
 drivers/gpu/drm/drm_fb_helper.c     |  1 -
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 3cf1aa132778..53e60daa1bb6 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -612,6 +612,13 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
 
 			return -EINVAL;
 		}
+		if (new_crtc_state->degamma_lut != old_crtc_state->degamma_lut ||
+		    new_crtc_state->ctm != old_crtc_state->ctm ||
+		    new_crtc_state->gamma_lut != old_crtc_state->gamma_lut) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] color management changed\n",
+					 crtc->base.id, crtc->name);
+			new_crtc_state->color_mgmt_changed = true;
+		}
 	}
 
 	ret = handle_conflicting_encoders(state, false);
@@ -3948,7 +3955,6 @@ int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
 	replaced  = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
 	replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
 	replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
-	crtc_state->color_mgmt_changed |= replaced;
 
 	ret = drm_atomic_commit(state);
 
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 26690a664ec6..686da206427e 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -434,29 +434,23 @@ static int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
 		drm_property_blob_put(mode);
 		return ret;
 	} else if (property == config->degamma_lut_property) {
-		ret = drm_atomic_replace_property_blob_from_id(dev,
+		return drm_atomic_replace_property_blob_from_id(dev,
 					&state->degamma_lut,
 					val,
 					-1, sizeof(struct drm_color_lut),
 					&replaced);
-		state->color_mgmt_changed |= replaced;
-		return ret;
 	} else if (property == config->ctm_property) {
-		ret = drm_atomic_replace_property_blob_from_id(dev,
+		return drm_atomic_replace_property_blob_from_id(dev,
 					&state->ctm,
 					val,
 					sizeof(struct drm_color_ctm), -1,
 					&replaced);
-		state->color_mgmt_changed |= replaced;
-		return ret;
 	} else if (property == config->gamma_lut_property) {
-		ret = drm_atomic_replace_property_blob_from_id(dev,
+		return drm_atomic_replace_property_blob_from_id(dev,
 					&state->gamma_lut,
 					val,
 					-1, sizeof(struct drm_color_lut),
 					&replaced);
-		state->color_mgmt_changed |= replaced;
-		return ret;
 	} else if (property == config->prop_out_fence_ptr) {
 		s32 __user *fence_ptr = u64_to_user_ptr(val);
 
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 73cf10adebbf..a53e169e6824 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1442,7 +1442,6 @@ static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
 		replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
 		replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
 						      gamma_lut);
-		crtc_state->color_mgmt_changed |= replaced;
 	}
 
 	ret = drm_atomic_commit(state);
-- 
2.18.0