Thomas Sailer wrote:
>
> Dan Streetman schrieb:
>
> > The URB is not automatically resubmitted by the HCD.
>
> BTW, what is the difference between such a nonresubmitted
> interrupt and a bulk transfer? Unless I'm missing something
> they look exactly the same on the wire, so why add another
> redundant interface?
>
Not exactly. A NAKed int transfer is just tried once in a frame;
a NAKed bulk transfer can retry often during a frame
(or more frames, so you even can loose bandwidth).
A int transfer should be guaranteed to have a free slot and just one
free slot within a period of time. There is no such guarantee for
bulk transfers.
Also if a HCD would use static, typed Endpoint-Descriptors there
would be a type mismatch.
(OHCI uses different HW-queues for int
and bulk transfers so if you mix them there could be some quirks).
(usb-ohci has semi-static Endpoint-Descriptors, but real static
Endpoint Descriptors could make more sense)
Roman
> Tom
>
> _______________________________________________
> [EMAIL PROTECTED]
> To unsubscribe, use the last form field at:
> http://lists.sourceforge.net/lists/listinfo/linux-usb-devel
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
http://lists.sourceforge.net/lists/listinfo/linux-usb-devel
