[PATCH v4 04/14] drm/rockchip: vop2: Fix the windows switch between different layers

[Andy Yan]

From: Andy Yan <andy.yan at rock-chips.com>

Every layer of vop2 should bind a window, and we also need to make
sure that this window is not used by other layer.

0x5 is a reserved layer sel value on rk3568, but it will select
Cluster3 on rk3588, configure unused layers to 0x5  will lead
alpha blending error on rk3588.

When we bind a window from layerM to layerN, we move the old window
on layerN to layerM.

Fixes: 604be85547ce ("drm/rockchip: Add VOP2 driver")
Signed-off-by: Andy Yan <andy.yan at rock-chips.com>
Tested-by: Derek Foreman <derek.foreman at collabora.com>
Tested-by: Michael Riesch <michael.riesch at wolfvision.net> # on RK3568
Tested-by: Detlev Casanova <detlev.casanova at collabora.com>
---

(no changes since v1)

 drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 38 +++++++++++++++-----
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
index c50d93df84046..4776a227e62c8 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
@@ -2364,7 +2364,9 @@ static void vop2_setup_layer_mixer(struct vop2_video_port *vp)
 	struct drm_plane *plane;
 	u32 layer_sel = 0;
 	u32 port_sel;
-	unsigned int nlayer, ofs;
+	u8 old_layer_id;
+	u8 layer_sel_id;
+	unsigned int ofs;
 	u32 ovl_ctrl;
 	int i;
 	struct vop2_video_port *vp0 = &vop2->vps[0];
@@ -2408,9 +2410,28 @@ static void vop2_setup_layer_mixer(struct vop2_video_port *vp)
 	for (i = 0; i < vp->id; i++)
 		ofs += vop2->vps[i].nlayers;
 
-	nlayer = 0;
 	drm_atomic_crtc_for_each_plane(plane, &vp->crtc) {
 		struct vop2_win *win = to_vop2_win(plane);
+		struct vop2_win *old_win;
+
+		/*
+		 * Find the layer this win bind in old state.
+		 */
+		for (old_layer_id = 0; old_layer_id < vop2->data->win_size; old_layer_id++) {
+			layer_sel_id = (layer_sel >> (4 * old_layer_id)) & 0xf;
+			if (layer_sel_id == win->data->layer_sel_id)
+				break;
+		}
+
+		/*
+		 * Find the win bind to this layer in old state
+		 */
+		for (i = 0; i < vop2->data->win_size; i++) {
+			old_win = &vop2->win[i];
+			layer_sel_id = (layer_sel >> (4 * (plane->state->normalized_zpos + ofs))) & 0xf;
+			if (layer_sel_id == old_win->data->layer_sel_id)
+				break;
+		}
 
 		switch (win->data->phys_id) {
 		case ROCKCHIP_VOP2_CLUSTER0:
@@ -2459,13 +2480,12 @@ static void vop2_setup_layer_mixer(struct vop2_video_port *vp)
 							  0x7);
 		layer_sel |= RK3568_OVL_LAYER_SEL__LAYER(plane->state->normalized_zpos + ofs,
 							 win->data->layer_sel_id);
-		nlayer++;
-	}
-
-	/* configure unused layers to 0x5 (reserved) */
-	for (; nlayer < vp->nlayers; nlayer++) {
-		layer_sel &= ~RK3568_OVL_LAYER_SEL__LAYER(nlayer + ofs, 0x7);
-		layer_sel |= RK3568_OVL_LAYER_SEL__LAYER(nlayer + ofs, 5);
+		/*
+		 * When we bind a window from layerM to layerN, we also need to move the old
+		 * window on layerN to layerM to avoid one window selected by two or more layers.
+		 */
+		layer_sel &= ~RK3568_OVL_LAYER_SEL__LAYER(old_layer_id, 0x7);
+		layer_sel |= RK3568_OVL_LAYER_SEL__LAYER(old_layer_id, old_win->data->layer_sel_id);
 	}
 
 	vop2_writel(vop2, RK3568_OVL_LAYER_SEL, layer_sel);
-- 
2.34.1