Session

The auxiliary bus gives us a clean way to split a single PCI device into multiple cooperating drivers, but its communication model is limited: the parent (aux_device creator) exposes data to the child (aux_driver), and the child consumes them. There is no first-class mechanism for either side to notify the other of events (asynchronous or synchronous) like link change, reset, FLR, capability change, config update, teardown intent, or specific kernel API calls targeted at the child but requiring parent resources to complete.