[PATCH v3 5/5] RFC: drm/atomic-helper: Reapply color transformation after resume

[Ezequiel Garcia]

Some platforms are not able to maintain the color transformation
state after a system suspend/resume cycle.

Set the colog_mgmt_changed flag so that CMM on the CRTCs in
the suspend state are reapplied after system resume.

Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
---
This is an RFC, and it's mostly based on Jacopo Mondi's work https://lkml.org/lkml/2019/9/6/498.

Changes from v2:
* New patch.
---
 drivers/gpu/drm/drm_atomic_helper.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index e41db0f202ca..518488125575 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3234,8 +3234,20 @@ int drm_atomic_helper_resume(struct drm_device *dev,
 			     struct drm_atomic_state *state)
 {
 	struct drm_modeset_acquire_ctx ctx;
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+	unsigned int i;
 	int err;
 
+	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
+		/*
+		 * Force re-enablement of CMM after system resume if any
+		 * of the DRM color transformation properties was set in
+		 * the state saved at system suspend time.
+		 */
+		if (crtc_state->gamma_lut)
+			crtc_state->color_mgmt_changed = true;
+	}
 	drm_mode_config_reset(dev);
 
 	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, err);
-- 
2.22.0