[PATCH 5.14 012/168] drm/amd/display: Fix white screen page fault for gpuvm

From: Greg Kroah-Hartman
Date: Mon Sep 20 2021 - 14:39:44 EST


From: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>

commit a70939851f9ced298dc7d523374b8c4d05239caf upstream.

[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@xxxxxxx>
Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>
Acked-by: Aaron Liu <aaron.liu@xxxxxxx>
Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 ++
1 file changed, 2 insertions(+)

--- 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(st
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);