From 47615028cde4d84c17138b803e9cb13f261ed129 Mon Sep 17 00:00:00 2001
From: Haowen Bai <baihaowen@meizu.com>
Date: Thu, 24 Mar 2022 17:46:02 +0800
Subject: drm/amd/display: Fix pointer dereferenced before checking
Git-commit: e84c8ab52dc76b09cb1c8885950ad4eaaf340bf6
Patch-mainline: v5.19-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

The value actual_pix_clk_100Hz is dereferencing pointer pix_clk_params
before pix_clk_params is being null checked. Fix this by assigning
pix_clk_params->requested_pix_clk_100hz to actual_pix_clk_100Hz only if
pix_clk_params is not NULL, otherwise just NULL.

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
index cc5128e67daf..c36f8e829344 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
@@ -1254,7 +1254,7 @@ static uint32_t dcn3_get_pix_clk_dividers(
 		struct pixel_clk_params *pix_clk_params,
 		struct pll_settings *pll_settings)
 {
-	unsigned long long actual_pix_clk_100Hz = pix_clk_params->requested_pix_clk_100hz;
+	unsigned long long actual_pix_clk_100Hz = pix_clk_params ? pix_clk_params->requested_pix_clk_100hz : 0;
 	struct dce110_clk_src *clk_src;
 
 	clk_src = TO_DCE110_CLK_SRC(cs);
-- 
2.38.1