On 27/10/17 04:48 PM, Christian König wrote: > Am 27.10.2017 um 16:37 schrieb Harry Wentland: >> On 2017-10-26 12:06 PM, Christian König wrote: >>> From: Christian König <christian.koenig at amd.com> >>> >>> Just set the bit so that DC does the hardware programming. >>> >>> Signed-off-by: Christian König <christian.koenig at 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 2188f20..ed4351a 100644 >>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c >>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c >>> @@ -417,6 +417,8 @@ static int amdgpu_dm_init(struct amdgpu_device >>> *adev) >>>       init_data.dce_environment = DCE_ENV_PRODUCTION_DRV; >>>  +   init_data.flags.gpu_vm_support = true; >>> + >> Hi Christian, >> >> what ASIC has this been tested on? > > Carizzo. > >> I'm not sure that this won't break dGPU. dGPU doesn't have vm_support >> but I think DC will still try to write the same registers as for CZ on >> dGPU if we enable this. We at least need to make sure it doesn't blow up. > > Yeah, as Tom already stumbled over as well it causes a warning on Tonga. > Currently giving it a spin on Polaris. > >> As for Raven we use this flag on Windows but only tested the case >> where VM is actually programmed. If VM isn't programmed it might still >> work but we'd need to give that a spin. > > Without this flag tilling fails and only displays a quite unusual pattern. > > I would actually prefer if we can completely remove this flag and > instead always enable the VM programming on supported hardware. > > Is there any downside on doing so? Is there a particular use-case for scanout from system memory with a dGPU? Otherwise I suspect it's better not to bother, because the failure mode might be pretty bad if the PCIe link can't keep up with scanout. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer
