drm_get_minor
int drm_get_minor(struct drm_device *dev, struct drm_minor **minor, int type);
ret = drm_get_minor(dev, &dev->control, DRM_MINOR_CONTROL);
if ((ret = drm_get_minor(dev, &dev->primary, DRM_MINOR_LEGACY)))
ret = drm_get_minor(dev, &dev->control, DRM_MINOR_CONTROL);
ret = drm_get_minor(dev, &dev->primary, DRM_MINOR_LEGACY);
EXPORT_SYMBOL(drm_get_minor);