From a70939851f9ced298dc7d523374b8c4d05239caf Mon Sep 17 00:00:00 2001
From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Date: Mon, 13 Sep 2021 14:56:44 -0400
Subject: drm/amd/display: Fix white screen page fault for gpuvm
Git-commit: a70939851f9ced298dc7d523374b8c4d05239caf
Patch-mainline: v5.15-rc2
References: bsc#1190786 stable-5.14.7
Alt-commit: a0f884f5abcde966af7b99766d2de8a729d6c6fd

[Why]
The "base_addr_is_mc_addr" field was added for dcn3.1 support but
pa_config was never updated to set it to false.

Uninitialized memory causes it to be set to true which results in
address mistranslation and white screen.

[How]
Use memset to ensure all fields are initialized to 0 by default.

Fixes: 64b1d0e8d500 ("drm/amd/display: Add DCN3.1 HWSEQ")
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Aaron Liu <aaron.liu@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>

---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 00b10879baf7f..66c799f5c7cf7 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -998,6 +998,8 @@ static void mmhub_read_system_context(struct amdgpu_device *adev, struct dc_phy_
 	uint32_t agp_base, agp_bot, agp_top;
 	PHYSICAL_ADDRESS_LOC page_table_start, page_table_end, page_table_base;
 
+	memset(pa_config, 0, sizeof(*pa_config));
+
 	logical_addr_low  = min(adev->gmc.fb_start, adev->gmc.agp_start) >> 18;
 	pt_base = amdgpu_gmc_pd_addr(adev->gart.bo);
 
-- 
2.33.0