drm/amdgpu: fix mode2 reset sequence for vangogh

We need to save and restore PCI config space.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>

drivers/gpu/drm/amd/amdgpu/nv.c

@@ -335,6 +335,38 @@ static int nv_asic_mode1_reset(struct amdgpu_device *adev)
 	return ret;
 }
 
+static int nv_asic_mode2_reset(struct amdgpu_device *adev)
+{
+	u32 i;
+	int ret = 0;
+
+	amdgpu_atombios_scratch_regs_engine_hung(adev, true);
+
+	/* disable BM */
+	pci_clear_master(adev->pdev);
+
+	amdgpu_device_cache_pci_state(adev->pdev);
+
+	ret = amdgpu_dpm_mode2_reset(adev);
+	if (ret)
+		dev_err(adev->dev, "GPU mode2 reset failed\n");
+
+	amdgpu_device_load_pci_state(adev->pdev);
+
+	/* wait for asic to come out of reset */
+	for (i = 0; i < adev->usec_timeout; i++) {
+		u32 memsize = adev->nbio.funcs->get_memsize(adev);
+
+		if (memsize != 0xffffffff)
+			break;
+		udelay(1);
+	}
+
+	amdgpu_atombios_scratch_regs_engine_hung(adev, false);
+
+	return ret;
+}
+
 static bool nv_asic_supports_baco(struct amdgpu_device *adev)
 {
 	struct smu_context *smu = &adev->smu;
@@ -392,7 +424,7 @@ static int nv_asic_reset(struct amdgpu_device *adev)
 		break;
 	case AMD_RESET_METHOD_MODE2:
 		dev_info(adev->dev, "MODE2 reset\n");
-		ret = amdgpu_dpm_mode2_reset(adev);
+		ret = nv_asic_mode2_reset(adev);
 		break;
 	default:
 		dev_info(adev->dev, "MODE1 reset\n");