On Mon, Mar 6, 2017 at 1:40 PM, Christian König <deathsimple@xxxxxxxxxxx> wrote: > From: Christian König <christian.koenig@xxxxxxx> > > Try to resize BAR0 to let CPU access all of VRAM. > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > @@ -616,6 +616,35 @@ void amdgpu_gtt_location(struct amdgpu_device *adev, struct amdgpu_mc *mc) > +void amdgpu_resize_bar0(struct amdgpu_device *adev) > +{ > + u32 size = max(ilog2(adev->mc.real_vram_size - 1) + 1, 20) - 20; Too complicated. unsigned long = fls_long(real_vram_size | BIT(20)); And the result is not a size, right? It's a logarithm from size. > + int r; > + > + r = pci_resize_resource(adev->pdev, 0, size); > + Redundant line. > + if (r == -ENOTSUPP) { > + /* The hardware don't support the extension. */ > + return; > + > + } else if (r == -ENOSPC) { > + DRM_INFO("Not enoigh PCI address space for a large BAR."); > + } else if (r) { > + DRM_ERROR("Problem resizing BAR0 (%d).", r); > + } > + > + /* Reinit the doorbell mapping, it is most likely moved as well */ > + amdgpu_doorbell_fini(adev); > + BUG_ON(amdgpu_doorbell_init(adev)); No way to recover?! > +} > + -- With Best Regards, Andy Shevchenko