--- a/drivers/gpu/drm/radeon/ci_dpm.c
+++ b/drivers/gpu/drm/radeon/ci_dpm.c
@@ -5655,6 +5655,14 @@
 		return -ENOMEM;
 	rdev->pm.dpm.priv = pi;
 
+	if (pci_is_root_bus(rdev->pdev->bus)) {
+		if (pi->sys_pcie_mask == 0)
+			pi->sys_pcie_mask = DRM_PCIE_SPEED_25 \
+				| PCI_EXP_LNKCAP2_SLS_5_0GB \
+				| PCI_EXP_LNKCAP2_SLS_8_0GB;
+		return 0;
+	}
+
 	ret = drm_pcie_get_speed_cap_mask(rdev->ddev, &mask);
 	if (ret)
 		pi->sys_pcie_mask = 0;