From: Roman Li <Roman.Li@xxxxxxx> [Why] Wrong fb offset results in dmub f/w errors and white screen. [drm:dc_dmub_srv_wait_idle [amdgpu]] *ERROR* Error waiting for DMUB idle: status=3 [How] Read aper_base from mmhub because GC is off by default v2: use BAR for passthrough (Alex) Signed-off-by: Roman Li <Roman.Li@xxxxxxx> Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> --- drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c index 11b61da419e7..b6daa4146dd3 100644 --- a/drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c @@ -685,6 +685,12 @@ static int gmc_v11_0_mc_init(struct amdgpu_device *adev) adev->gmc.aper_base = pci_resource_start(adev->pdev, 0); adev->gmc.aper_size = pci_resource_len(adev->pdev, 0); +#ifdef CONFIG_X86_64 + if ((adev->flags & AMD_IS_APU) && !amdgpu_passthrough(adev)) { + adev->gmc.aper_base = adev->mmhub.funcs->get_mc_fb_offset(adev); + adev->gmc.aper_size = adev->gmc.real_vram_size; + } +#endif /* In case the PCI BAR is larger than the actual amount of vram */ adev->gmc.visible_vram_size = adev->gmc.aper_size; if (adev->gmc.visible_vram_size > adev->gmc.real_vram_size) -- 2.35.3