drm/omap: Add a 'right overlay' to plane state

If the drm_plane has a source width that's greater than the max width
supported by a single hw overlay, then we assign a 'r_overlay' to it in
omap_plane_atomic_check().

Both overlays should have the capabilities required to handle the source
framebuffer. The only parameters that vary between the left and right
hwoverlays are the src_w, crtc_w, src_x and crtc_x as we just even chop
the fb into left and right halves.

We also take care of not creating odd width size when dealing with YUV
formats.

Since both halves need to be 'appear' side by side the zpos is
recalculated when dealing with dual overlay cases so that the other
planes zpos is consistent.

Depending on user space usage it is possible that on occasion the number
of requested planes exceeds the numbers of overlays required to display
them. In that case a failure would be returned for the plane that cannot
be handled at that time. It is up to user space to make sure the H/W
resource are not over-subscribed.

Signed-off-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211117141928.771082-10-narmstrong@baylibre.com

1 files changed, 97 insertions, 1 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
index 44a9dcb3100c..2720a58ccd90 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -117,6 +117,102 @@ static void omap_atomic_commit_tail(struct drm_atomic_state *old_state)
 	dispc_runtime_put(priv->dispc);
 }
 
+static int drm_atomic_state_normalized_zpos_cmp(const void *a, const void *b)
+{
+	const struct drm_plane_state *sa = *(struct drm_plane_state **)a;
+	const struct drm_plane_state *sb = *(struct drm_plane_state **)b;
+
+	if (sa->normalized_zpos != sb->normalized_zpos)
+		return sa->normalized_zpos - sb->normalized_zpos;
+	else
+		return sa->plane->base.id - sb->plane->base.id;
+}
+
+/*
+ * This replaces the drm_atomic_normalize_zpos to handle the dual overlay case.
+ *
+ * Since both halves need to be 'appear' side by side the zpos is
+ * recalculated when dealing with dual overlay cases so that the other
+ * planes zpos is consistent.
+ */
+static int omap_atomic_update_normalize_zpos(struct drm_device *dev,
+					     struct drm_atomic_state *state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_state, *new_state;
+	struct drm_plane *plane;
+	int c, i, n, inc;
+	int total_planes = dev->mode_config.num_total_plane;
+	struct drm_plane_state **states;
+	int ret = 0;
+
+	states = kmalloc_array(total_planes, sizeof(*states), GFP_KERNEL);
+	if (!states)
+		return -ENOMEM;
+
+	for_each_oldnew_crtc_in_state(state, crtc, old_state, new_state, c) {
+		if (old_state->plane_mask == new_state->plane_mask &&
+		    !new_state->zpos_changed)
+			continue;
+
+		/* Reset plane increment and index value for every crtc */
+		n = 0;
+
+		/*
+		 * Normalization process might create new states for planes
+		 * which normalized_zpos has to be recalculated.
+		 */
+		drm_for_each_plane_mask(plane, dev, new_state->plane_mask) {
+			struct drm_plane_state *plane_state =
+				drm_atomic_get_plane_state(new_state->state,
+							   plane);
+			if (IS_ERR(plane_state)) {
+				ret = PTR_ERR(plane_state);
+				goto done;
+			}
+			states[n++] = plane_state;
+		}
+
+		sort(states, n, sizeof(*states),
+		     drm_atomic_state_normalized_zpos_cmp, NULL);
+
+		for (i = 0, inc = 0; i < n; i++) {
+			plane = states[i]->plane;
+
+			states[i]->normalized_zpos = i + inc;
+			DRM_DEBUG_ATOMIC("[PLANE:%d:%s] updated normalized zpos value %d\n",
+					 plane->base.id, plane->name,
+					 states[i]->normalized_zpos);
+
+			if (is_omap_plane_dual_overlay(states[i]))
+				inc++;
+		}
+		new_state->zpos_changed = true;
+	}
+
+done:
+	kfree(states);
+	return ret;
+}
+
+static int omap_atomic_check(struct drm_device *dev,
+			     struct drm_atomic_state *state)
+{
+	int ret;
+
+	ret = drm_atomic_helper_check(dev, state);
+	if (ret)
+		return ret;
+
+	if (dev->mode_config.normalize_zpos) {
+		ret = omap_atomic_update_normalize_zpos(dev, state);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static const struct drm_mode_config_helper_funcs omap_mode_config_helper_funcs = {
 	.atomic_commit_tail = omap_atomic_commit_tail,
 };
@@ -124,7 +220,7 @@ static const struct drm_mode_config_helper_funcs omap_mode_config_helper_funcs =
 static const struct drm_mode_config_funcs omap_mode_config_funcs = {
 	.fb_create = omap_framebuffer_create,
 	.output_poll_changed = drm_fb_helper_output_poll_changed,
-	.atomic_check = drm_atomic_helper_check,
+	.atomic_check = omap_atomic_check,
 	.atomic_commit = drm_atomic_helper_commit,
 };