[PATCH 1/5] drm/rockchip: vop2: Fix wrong wait target in layer cfg done check

[Cristian Ciocaltea]

rk3568_vop2_setup_layer_mixer() waits for the previous Video Port (VP)
layer configuration to take effect before writing a new one to the
shared RK3568_OVL_LAYER_SEL shadow register.  However, it passes
vop2->old_layer_sel to rk3568_vop2_wait_for_layer_cfg_done() as the
expected value, which at that point already contains the new VP layer.

This causes the wait to poll for a value that has not been written to
the shadow register yet, resulting in spurious timeouts when two
non-blocking atomic commits race:

  rockchip-drm display-subsystem: [drm] *ERROR* wait layer cfg done timeout [...]

Pass the local old_layer_sel instead, which still holds the value
captured from vop2->old_layer_sel before it was overwritten, i.e. the
previous VP target that the hardware is expected to latch.

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 at collabora.com>
---
 drivers/gpu/drm/rockchip/rockchip_vop2_reg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_vop2_reg.c b/drivers/gpu/drm/rockchip/rockchip_vop2_reg.c
index 02a788a4dfdd..edca0fb16e08 100644
--- a/drivers/gpu/drm/rockchip/rockchip_vop2_reg.c
+++ b/drivers/gpu/drm/rockchip/rockchip_vop2_reg.c
@@ -2307,7 +2307,7 @@ static void rk3568_vop2_setup_layer_mixer(struct vop2_video_port *vp)
 		 * Changes of other VPs' overlays have not taken effect
 		 */
 		if (cfg_done)
-			rk3568_vop2_wait_for_layer_cfg_done(vop2, vop2->old_layer_sel);
+			rk3568_vop2_wait_for_layer_cfg_done(vop2, old_layer_sel);
 	}
 
 	vop2_writel(vop2, RK3568_OVL_LAYER_SEL, layer_sel);

-- 
2.53.0