[PATCH 1/1] drm/amdgpu: Use GTT for dumb buffer if sg display enabled

[Christian König]

Am 22.05.2018 um 09:09 schrieb Michel Dänzer:
> On 2018-05-22 01:22 AM, Deepak Sharma wrote:
>> When vram size <= THRESHOLD(256M) lets use GTT for dumb buffer
>> allocation. As SG will be enabled with vram size <= 256M
>> scan out will not be an issue.
>>
>> Signed-off-by: Deepak Sharma <Deepak.Sharma at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 7 +++++--
>>   1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>> index 2c8e27370284..c547d92dbf4e 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>> @@ -749,15 +749,18 @@ int amdgpu_mode_dumb_create(struct drm_file *file_priv,
>>   	struct amdgpu_device *adev = dev->dev_private;
>>   	struct drm_gem_object *gobj;
>>   	uint32_t handle;
>> +	u32 domain;
>>   	int r;
>>   
>>   	args->pitch = amdgpu_align_pitch(adev, args->width,
>>   					 DIV_ROUND_UP(args->bpp, 8), 0);
>>   	args->size = (u64)args->pitch * args->height;
>>   	args->size = ALIGN(args->size, PAGE_SIZE);
>> +	domain = AMDGPU_GEM_DOMAIN_VRAM;
>> +	if (adev->gmc.real_vram_size <= AMDGPU_SG_THRESHOLD)
>> +		domain = AMDGPU_GEM_DOMAIN_GTT;
> This could choose GTT even in cases where scanout from that isn't
> supported.
>
> It should call amdgpu_display_supported_domains, and then use the same
> logic as in amdgpu_bo_pin_restricted:
>
>          if (domain == (AMDGPU_GEM_DOMAIN_VRAM | AMDGPU_GEM_DOMAIN_GTT)) {
>                  domain = AMDGPU_GEM_DOMAIN_VRAM;
>                  if (adev->gmc.real_vram_size <= AMDGPU_SG_THRESHOLD)
>                          domain = AMDGPU_GEM_DOMAIN_GTT;
>          }
>
> Maybe this logic could be refactored into a helper function.

Actually you don't even need that logic here. All you need to do is to 
use amdgpu_display_supported_domains and you're done.

The BO is moved to the correct place when it is pinned for scanout or 
use with the fb interface.

Regards,
Christian.