From 203ccaf586446b578909de1b763278033fb74b51 Mon Sep 17 00:00:00 2001
From: Haiyi Zhou <Haiyi.Zhou@amd.com>
Date: Thu, 20 Oct 2022 11:46:54 -0400
Subject: [PATCH] drm/amd/display: wait for vblank during pipe programming
Git-commit: 203ccaf586446b578909de1b763278033fb74b51
Patch-mainline: v6.2-rc1
References: git-fixes

[WHY]
Skipping vblank during global sync update request can result in
underflow on certain displays.

[HOW]
Roll back to the previous behavior where DC waits for vblank during pipe
programming.

Fixes: 5d3e14421410 ("drm/amd/display: do not wait for vblank during pipe programming")
Tested-by: Mark Broadworth <mark.broadworth@amd.com>
Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Haiyi Zhou <Haiyi.Zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

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 1ac0ed5be605..feff834d5410 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1640,10 +1640,8 @@ static void dcn20_program_pipe(
 				pipe_ctx->pipe_dlg_param.vupdate_width);
 
 		if (pipe_ctx->stream->mall_stream_config.type != SUBVP_PHANTOM) {
-			pipe_ctx->stream_res.tg->funcs->wait_for_state(
-				pipe_ctx->stream_res.tg, CRTC_STATE_VBLANK);
-			pipe_ctx->stream_res.tg->funcs->wait_for_state(
-				pipe_ctx->stream_res.tg, CRTC_STATE_VACTIVE);
+			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VBLANK);
+			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VACTIVE);
 		}
 
 		pipe_ctx->stream_res.tg->funcs->set_vtg_params(
-- 
2.35.3