Re: [PATCH v27 01/32] xhci: add helper to stop endpoint and wait for completion

["Michał Pecio" <michal.pecio@gmail.com>]

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