[PATCH 47/87] drm/amd/display: Wait for flip to complete

[sunpeng.li at amd.com]

From: Alvin Lee <alvin.lee2 at amd.com>

[why]
In pipe split issue occurs when we program immediate flip while vsync flip is pending

[how]
Don't program immediate flip until flip is no longer pending

Signed-off-by: Alvin Lee <alvin.lee2 at amd.com>
Reviewed-by: Jaehyun Chung <Jaehyun.Chung at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
index a918f2770c38..9c0a788fbb18 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1283,6 +1283,17 @@ void dcn20_pipe_control_lock(
 	if (pipe->plane_state != NULL)
 		flip_immediate = pipe->plane_state->flip_immediate;
 
+	if (flip_immediate && lock) {
+		while (pipe->plane_res.hubp->funcs->hubp_is_flip_pending(pipe->plane_res.hubp))	{
+			udelay(1);
+		}
+
+		if (pipe->bottom_pipe != NULL)
+			while (pipe->bottom_pipe->plane_res.hubp->funcs->hubp_is_flip_pending(pipe->bottom_pipe->plane_res.hubp))	{
+				udelay(1);
+			}
+	}
+
 	/* In flip immediate and pipe splitting case, we need to use GSL
 	 * for synchronization. Only do setup on locking and on flip type change.
 	 */
-- 
2.22.0