From f5c4b23b56f5efbdeebfa93ec56534d9d2c09d7b Mon Sep 17 00:00:00 2001
From: Sung Lee <sung.lee@amd.com>
Date: Sun, 5 Apr 2020 16:40:48 -0400
Subject: drm/amd/display: Check power_down functions exist before calling
Git-commit: d5e27f072844f6097ab3305b3b7bee00709b953b
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

[WHY]
The power_down() function was only defined for specific asics and will
crash the system if it is called by an asic with eDP connected that does
not have it defined.

[HOW]
Add a check for the function's existence before calling it.

Signed-off-by: Sung Lee <sung.lee@amd.com>
Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index 9bed5e885fed..ea39656b884f 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -1378,8 +1378,11 @@ void dcn10_init_hw(struct dc *dc)
 		struct dc_link *edp_link = get_edp_link(dc);
 
 		if (edp_link &&
-			edp_link->link_enc->funcs->is_dig_enabled &&
-			edp_link->link_enc->funcs->is_dig_enabled(edp_link->link_enc)) {
+				edp_link->link_enc->funcs->is_dig_enabled &&
+				edp_link->link_enc->funcs->is_dig_enabled(edp_link->link_enc) &&
+				dc->hwss.edp_backlight_control &&
+				dc->hwss.power_down &&
+				dc->hwss.edp_power_control) {
 			dc->hwss.edp_backlight_control(edp_link, false);
 			dc->hwss.power_down(dc);
 			dc->hwss.edp_power_control(edp_link, false);
-- 
2.28.0