From: Yogesh Mohan Marimuthu <yogesh.mohanmarimuthu@amd.com>
Date: Fri, 2 Aug 2019 10:52:49 +0530
Subject: drm/amd/display: fix trigger not generated for freesync
Git-commit: 1e7f100ce8c0640634b794604880d9204480c9f1
Patch-mainline: 5.4-rc1
References: bnc#1151927 5.3.5

[Why]
In newer hardware MANUAL_FLOW_CONTROL is not a trigger bit. Due to this
front porch is fixed and in these hardware freesync does not work.

[How]
Change the programming to generate a pulse so that the event will be
triggered, front porch will be cut short and freesync will work.

Signed-off-by: Yogesh Mohan Marimuthu <yogesh.mohanmarimuthu@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c
@@ -824,6 +824,9 @@ void optc1_program_manual_trigger(struct
 
 	REG_SET(OTG_MANUAL_FLOW_CONTROL, 0,
 			MANUAL_FLOW_CONTROL, 1);
+
+	REG_SET(OTG_MANUAL_FLOW_CONTROL, 0,
+			MANUAL_FLOW_CONTROL, 0);
 }