From 581378d3565aa7ffb35b0900a341a2a731da19a5 Mon Sep 17 00:00:00 2001
From: Martin Leung <martin.leung@amd.com>
Date: Wed, 30 Oct 2019 14:19:30 -0400
Subject: drm/amd/display: Add null check to dc_submit_i2c_oem
Git-commit: ac78fa502afa539cce3a285e50d7fefaf4d2115e
Patch-mainline: v6.0-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849

[why]
dc_submit_i2c_oem could be called with ddc null

[how]
add null check and fail the call instead

Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Martin Leung <martin.leung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/dc/core/dc.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 49339c5c7230..258322c39e9a 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -3477,10 +3477,13 @@ bool dc_submit_i2c_oem(
 		struct i2c_command *cmd)
 {
 	struct ddc_service *ddc = dc->res_pool->oem_device;
-	return dce_i2c_submit_command(
-		dc->res_pool,
-		ddc->ddc_pin,
-		cmd);
+	if (ddc)
+		return dce_i2c_submit_command(
+			dc->res_pool,
+			ddc->ddc_pin,
+			cmd);
+
+	return false;
 }
 
 static bool link_add_remote_sink_helper(struct dc_link *dc_link, struct dc_sink *sink)
-- 
2.38.1