Apparatuses, methods, and computer-readable media are provided for operating a port manager to detect a first link condition or a second link condition of a circuitry. Under the first link condition, a first link between a downstream port of the circuitry and an upstream port of a switch is compatible to a first protocol, and a second link between a downstream port of the switch and an upstream port of a device is compatible to the second protocol. Under the second link condition, the first link exists and is compatible to the first protocol, while there is no second link being compatible to the second protocol. The port manager is to operate the downstream port of the circuitry according to the second protocol on detection of the first link condition, or according to the first protocol on detection of the second link condition. Other embodiments may be described and/or claimed.