[PATCH v4] drm/omap: plane zpos/zorder management improvements

[Peter Ujfalusi]

Use the plane index as default zpos for all planes. Even if the
application is not setting zpos/zorder explicitly we will have unique zpos
for each plane.

Enforce that all planes must have unique zpos on the given crtc.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
---
Hi,

Changes since v3:
- Use drm_plane_index() instead of storing the same index wothin omap_plane
  struct
- Optimize the zpos validation loop so we avoid extra checks.

Changes since v2:
- The check for duplicate zpos is moved to omap_crtc

Changes since v1:
- Dropped the zpos normalization related patches
- New patch based on the discussion, see commit message.

Regards,
Peter

 drivers/gpu/drm/omapdrm/omap_crtc.c  | 36 +++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/omapdrm/omap_plane.c | 15 ++++-----------
 2 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
index cc85c16cbc2a..c68e3a4f5b7d 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -452,6 +452,40 @@ static void omap_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	}
 }
 
+static int omap_crtc_validate_zpos(struct drm_crtc *crtc,
+				   struct drm_crtc_state *state)
+{
+	struct drm_device *ddev = crtc->dev;
+	struct drm_plane *p1;
+	const struct drm_plane_state *pstate1;
+
+	/* Check the crts's planes against duplicated zpos value */
+	drm_atomic_crtc_state_for_each_plane_state(p1, pstate1, state) {
+		struct drm_plane *p2 = p1;
+
+		list_for_each_entry_continue(p2, &ddev->mode_config.plane_list,
+					     head) {
+			const struct drm_plane_state *pstate2;
+
+			if (!(state->plane_mask & (1 << drm_plane_index(p2))))
+				continue;
+
+			pstate2 = __drm_atomic_get_current_plane_state(
+							state->state, p2);
+			if (!pstate2)
+				continue;
+
+			if (pstate1->zpos == pstate2->zpos) {
+				DBG("crtc%u: zpos must be unique (zpos: %u)",
+				crtc->index, pstate1->zpos);
+				return -EINVAL;
+			}
+		}
+	}
+
+	return 0;
+}
+
 static int omap_crtc_atomic_check(struct drm_crtc *crtc,
 				struct drm_crtc_state *state)
 {
@@ -475,7 +509,7 @@ static int omap_crtc_atomic_check(struct drm_crtc *crtc,
 		omap_crtc_state->rotation = pri_state->rotation;
 	}
 
-	return 0;
+	return omap_crtc_validate_zpos(crtc, state);
 }
 
 static void omap_crtc_atomic_begin(struct drm_crtc *crtc,
diff --git a/drivers/gpu/drm/omapdrm/omap_plane.c b/drivers/gpu/drm/omapdrm/omap_plane.c
index 15e5d5d325c6..d0057a23a5ac 100644
--- a/drivers/gpu/drm/omapdrm/omap_plane.c
+++ b/drivers/gpu/drm/omapdrm/omap_plane.c
@@ -99,8 +99,7 @@ static void omap_plane_atomic_disable(struct drm_plane *plane,
 	struct omap_plane *omap_plane = to_omap_plane(plane);
 
 	plane->state->rotation = DRM_MODE_ROTATE_0;
-	plane->state->zpos = plane->type == DRM_PLANE_TYPE_PRIMARY
-			   ? 0 : omap_plane->id;
+	plane->state->zpos = drm_plane_index(plane);
 
 	priv->dispc_ops->ovl_enable(omap_plane->id, false);
 }
@@ -186,18 +185,12 @@ void omap_plane_install_properties(struct drm_plane *plane,
 
 static void omap_plane_reset(struct drm_plane *plane)
 {
-	struct omap_plane *omap_plane = to_omap_plane(plane);
-
 	drm_atomic_helper_plane_reset(plane);
 	if (!plane->state)
 		return;
 
-	/*
-	 * Set the zpos default depending on whether we are a primary or overlay
-	 * plane.
-	 */
-	plane->state->zpos = plane->type == DRM_PLANE_TYPE_PRIMARY
-			   ? 0 : omap_plane->id;
+	/* Set the zpos to the plane index. */
+	plane->state->zpos = drm_plane_index(plane);
 }
 
 static int omap_plane_atomic_set_property(struct drm_plane *plane,
@@ -297,7 +290,7 @@ struct drm_plane *omap_plane_init(struct drm_device *dev,
 	drm_plane_helper_add(plane, &omap_plane_helper_funcs);
 
 	omap_plane_install_properties(plane, &plane->base);
-	drm_plane_create_zpos_property(plane, 0, 0, num_planes - 1);
+	drm_plane_create_zpos_property(plane, idx, 0, num_planes - 1);
 
 	return plane;
 
-- 
Peter

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