In a particular embodiment, a method is disclosed that includes, at a first computing device coupled to a second computing device via a bus, receiving a request from the second computing device to complete a non-posted command, where the request is received via a request credit channel of the bus, and where the first computing device is configured to receive requests to complete non-posted commands and requests to complete posted commands via the request credit channel. The method also includes removing the request to complete the non-posted command from the request credit channel. The method further includes transmitting a retry request associated with the non-posted command to the second computing device via a response credit channel of the bus.