Hi, > Expose xhci_stop_endpoint_sync() which is a synchronous variant of > xhci_queue_stop_endpoint(). This is useful for client drivers that are > using the secondary interrupters, and need to stop/clean up the current > session. The stop endpoint command handler will also take care of > cleaning up the ring. I'm not entirely sure what you meant by "cleaning up the ring" (maybe a comment would be in order?), but I see nothing being done here after the command completes and FYI xhci-ring.c will not run the default handler if the command is queued with a completion, like here. At least that's the case for certain command types and there is probably a story behind each of them. I know that xhci_stop_device() queues a Stop EP with completion (and also a few without(?)). Maybe it's a bug... Regards, Michal