Re: [PATCH] drm/amd/display: Fix white screen page fault for gpuvm

["Kazlauskas, Nicholas" <nicholas.kazlauskas@amd.com>]

On 2021-09-13 3:13 p.m., Alex Deucher wrote:
> Acked-by: Alex Deucher <alexander.deucher@amd.com>
> 
> Can you add a fixes: tag?
> 
> Alex

Sure, I think the relevant patch is:

Fixes: 64b1d0e8d50 ("drm/amd/display: Add DCN3.1 HWSEQ")

Regards,
Nicholas Kazlauskas

> 
> On Mon, Sep 13, 2021 at 3:11 PM Nicholas Kazlauskas
> <nicholas.kazlauskas@amd.com> wrote:
>>
>> [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.
>>
>> Cc: Aaron Liu <aaron.liu@amd.com>
>> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
>> ---
>>   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 53363728dbb..b0426bb3f2e 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -1125,6 +1125,8 @@ 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);
>>
>> --
>> 2.25.1
>>