2005/9/6, David Brownell <[EMAIL PROTECTED]>:
> Again, _transfers_ don't reserve bandwidth, endpoints do.
>
I think I misunderstood this point....
> And when the endpoint's transfer queue is empty, it surrenders
> its bandwidth reservation.
>
Dave, I just want to be sure to well understand this driver, because
I'm writing one which is similar to the sl811 one. So I hope you don't
mind if I'm asking several questions again :)
When you say NAK is not an error case, this is true except for setup
stage. Functions cannot issue a NAK packet in response to a setup
packet. In that case, it is an _error_, is it correct ?
Most important question, let say for an interrupt point "URB1" is
submitted. The HCD checks that this endpoint is not already scheduled
and if not it schedules it if there's enough bandwidth. Now "URB2" is
submitted for the same endpoint and "URB1" is still in the queue. The
driver detects that the endpoint is already scheduled and so does
nothing (BTW, URB2->start_frame is not setup, isn't it ?). Why
bandwith allocation is not done ? Now "URB1" is processed and
"finish_request" is called. "URB2" is the next periodic transfer in
the queue and so is the next transfer for this endpoint. it seems to
be started in the same frame as "URB1", shouldn't it be started for
the next period ?
In "finish_request", if the endpoint has not more transaction in its
queue, when is "ep" variable freed ?
Thanks !
--
Franck
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