Am Donnerstag, 10. Februar 2005 17:25 schrieb Alan Stern:
> On Thu, 10 Feb 2005, Oliver Neukum wrote:
>
> > Am Donnerstag, 10. Februar 2005 16:41 schrieb Alan Stern:
> > > We've discussed in the past that the notion of unlinking a single URB is
> > > unnatural. When a driver has multiple URBs queued for an endpoint it will
> > > always want to unlink all of them together; it will never want to unlink
> > > only some -- that wouldn't make any sense. Furthermore it's a lot easier
> > > for HCDs to clear out all the URBs queued for an endpoint than to remove
> > > just one of them.
> >
> > What about the timeout handling in network drivers?
>
> I have no idea; I don't know how USB network interfaces work. Are you
> talking about OUT URBs? Are they all more or less independent, in the
> sense that each can have its own timeout and it doesn't matter much which
> ones get sent and which ones don't? How is the timeout handling supposed
> to work?
For simply net devices all outstanding packets are canceled. But are you
really sure that no interface at all needs selective unlinking? This broad
sweeping statement about "naturalness" makes me nervous, especially
as unlinking what you submitted seems more natural to me than
a mass unlink.
> How does the design of the USB network class fit in with the notion that a
> bulk pipe transmits a single, reliable, logical stream of data? Networks
> aren't like that; they transmit unreliably many independent packets.
Neither is USB. There is the rule about short and zero packets in the spec.
USB is clearly packetized, not a streaming protocol.
Regards
Oliver
-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_ide95&alloc_id396&op=click
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
