> The first question is not specific to sl811 hcd: for periodic
> transfer, does a urb must be resubmitted by the function driver after
> its transfer completion is called or is it handled by the hcd/core ?

There is no "automagic resubmit" in 2.6 kernels; drivers reissue URBs
themselves, if that's what they want.  (And they handle any errors
themselves, rather than having usbcore or the hcd ignore them.)


> The second question is specific to sl811: periodic deschedules appear
> in "finish_request" function. I don't understand the conditions needed
> to start the periodic deschedule process. Does it happen when no more
> transfer is pending for the current frame ?

If the periodic endpoint in question has an empty transfer queue when the
completion function returns, there's no point in leaving that endpoint in
the schedule ... so it gets descheduled.  After all, there'd be no point
in leaving that part of the schedule reserved, if the driver stops using
the slot which was temporarily reserved for it.

- Dave
 


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