* this used to be a separate function in drm_dma.h
         */
 
+       if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
+               return 0;
+       if (drm_core_check_feature(dev, DRIVER_MODESET))
+               return 0;
+       /* UMS was only ever support on pci devices. */
+       if (WARN_ON(!dev->pdev))
+               return -EINVAL;
 
        switch (ctl->func) {
        case DRM_INST_HANDLER:
-               if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
-                       return 0;
-               if (drm_core_check_feature(dev, DRIVER_MODESET))
-                       return 0;
                if (dev->if_version < DRM_IF_VERSION(1, 2) &&
                    ctl->irq != drm_dev_to_irq(dev))
                        return -EINVAL;
                return drm_irq_install(dev);
        case DRM_UNINST_HANDLER:
-               if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
-                       return 0;
-               if (drm_core_check_feature(dev, DRIVER_MODESET))
-                       return 0;
                return drm_irq_uninstall(dev);
        default:
                return -EINVAL;