[PATCH] drm/amd/display: Enable VM support only on APUs newer than CZ

[Christian König]

Am 30.10.2017 um 19:52 schrieb Harry Wentland:
> On 2017-10-30 02:00 PM, Christian König wrote:
>> Am 30.10.2017 um 18:41 schrieb Harry Wentland:
>>> VM support is only available for CZ and newer APUs. Trying to
>>> enable it for dGPU will blow up in DC.
>>>
>>> Signed-off-by: Harry Wentland <harry.wentland at amd.com>
>>> Suggested-by: Alex Deucher <alexander.deucher at amd.com>
>>> CC: Christian Koenig <christian.koenig at amd.com>
>> Ok, with me. But I think it would be cleaner if the backend can just handle this gracefully even when it is not supported by the hardware.
>>
> Yes, I think we're all agreed on this. I just thought I'd send out something because it looked like it might be urgent. This is kind-of unplanned work for me and not on top of my list with everything else that's happening right now.

Calm down, that isn't even remotely urgent. I would like to finish it 
before 4.15, but we have at least two weeks before the next merge window.

And even then I don't think it would hurt us to much if we need to wait 
for 4.16.

Christian.

>
> Harry
>
>> Christian.
>>
>>> ---
>>>    drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++++
>>>    1 file changed, 4 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 26f6d5e4c08c..332761f643f6 100644
>>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>> @@ -427,6 +427,10 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
>>>            amdgpu_dm_initialize_fbc(adev);
>>>        init_data.fbc_gpu_addr = adev->dm.compressor.gpu_addr;
>>>    #endif
>>> +
>>> +    if (adev->flags & AMD_IS_APU && adev->asic_type >= CHIP_CARRIZO)
>>> +        init_data.flags.gpu_vm_support = true;
>>> +
>>>        /* Display Core create. */
>>>        adev->dm.dc = dc_create(&init_data);
>>>    
>>