On Thu, 20 Dec 2007, David Brownell wrote: > On Thursday 20 December 2007, Alan Stern wrote: > > I'm not aware of any way in which the EHCI hardware under Linux can be > > slowed down. There _is_ a way in which it could be sped up: Set the > > "park" module parameter for ehci-hcd to something larger than 0. > > You may have noticed that the hardware default of _using_ that "park" > mechanism is disabled ... because in one test scenario I observed that > it actually slowed down the transfer! One of these day's I'll have to > watch what happens "on the wire" to see why it wasn't a speedup.
Maybe Windows does it, and as a result runs slower! :-) > I also got a report of some USB sticks that didn't like to see the PING > packets during EP0 transfers. Now I've got to see whether the USB spec > even allows those ... and in any case, how to disable pinging on EP0 > when using EHCI. I think it does allow PINGs during the data stage of a control-OUT transfer. And I don't recall seeing anything outlawing PINGs during the status stage of a control-IN transfer, although they would be almost pointless. Alan Stern - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
