[PATCH 2/5] drm/rockchip: vop2: Wait for layer cfg done before switching LAYERSEL_REGDONE_SEL

[Cristian Ciocaltea <cristian.ciocaltea@collabora.com>]

LAYERSEL_REGDONE_SEL mask of RK3568_OVL_CTRL register controls which
Video Port (VP) vsync latches the shared RK3568_OVL_{LAYER|PORT}_SEL
shadow registers into the active configuration.

rk3568_vop2_setup_layer_mixer() overwrites LAYERSEL_REGDONE_SEL to the
current VP ID before waiting for the previous VP layer configuration to
take effect.  As a consequence, the previous VP vsync can no longer
trigger the latch, so the wait polls a value that might never appear.

Move the layer cfg done wait before the RK3568_OVL_CTRL write so the
previous VP vsync can still commit the pending configuration.

Fixes: 3e89a8c68354 ("drm/rockchip: vop2: Fix the update of LAYER/PORT select registers when there are multi display output on rk3588/rk3568")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/rockchip/rockchip_vop2_reg.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_vop2_reg.c b/drivers/gpu/drm/rockchip/rockchip_vop2_reg.c
index edca0fb16e08..5206f01ec787 100644
--- a/drivers/gpu/drm/rockchip/rockchip_vop2_reg.c
+++ b/drivers/gpu/drm/rockchip/rockchip_vop2_reg.c
@@ -2289,15 +2289,6 @@ static void rk3568_vop2_setup_layer_mixer(struct vop2_video_port *vp)
 	 *    lead to the configuration of the previous VP being take effect along with the VSYNC
 	 *    of the new VP.
 	 */
-	if (layer_sel != old_layer_sel || port_sel != old_port_sel)
-		ovl_ctrl |= FIELD_PREP(RK3568_OVL_CTRL__LAYERSEL_REGDONE_SEL, vp->id);
-	vop2_writel(vop2, RK3568_OVL_CTRL, ovl_ctrl);
-
-	if (port_sel != old_port_sel) {
-		vop2_writel(vop2, RK3568_OVL_PORT_SEL, port_sel);
-		vop2_cfg_done(vp);
-		rk3568_vop2_wait_for_port_mux_done(vop2);
-	}
 
 	if (layer_sel != old_layer_sel && atv_layer_sel != old_layer_sel) {
 		cfg_done = vop2_readl(vop2, RK3568_REG_CFG_DONE);
@@ -2310,6 +2301,16 @@ static void rk3568_vop2_setup_layer_mixer(struct vop2_video_port *vp)
 			rk3568_vop2_wait_for_layer_cfg_done(vop2, old_layer_sel);
 	}
 
+	if (layer_sel != old_layer_sel || port_sel != old_port_sel)
+		ovl_ctrl |= FIELD_PREP(RK3568_OVL_CTRL__LAYERSEL_REGDONE_SEL, vp->id);
+	vop2_writel(vop2, RK3568_OVL_CTRL, ovl_ctrl);
+
+	if (port_sel != old_port_sel) {
+		vop2_writel(vop2, RK3568_OVL_PORT_SEL, port_sel);
+		vop2_cfg_done(vp);
+		rk3568_vop2_wait_for_port_mux_done(vop2);
+	}
+
 	vop2_writel(vop2, RK3568_OVL_LAYER_SEL, layer_sel);
 	mutex_unlock(&vop2->ovl_lock);
 }

-- 
2.53.0