On Saturday 30 October 2004 07:40, Alan Stern wrote: > On Fri, 29 Oct 2004, N Lin wrote: > > > My understanding of the proper behavior (please correct me > > if I'm wrong) is that the EHCI driver would handle the USB2 > > transfers over this card, but if a USB1 device is connected > > to the hub then the EHCI module will pass the handling on to > > the companion UHCI driver to do the USB1 stuff.
That's how it should work: EHCI handles high speed, companion handles low and full speed. Unless you have an external hub with a transaction translator (TT); and some embedded hardware integrates the TT, but finding that on a PCMCIA card would be strange. > (Technically, if the hcd->start callback fails then hcd->stop should not > be invoked -- but it is. David, will the EHCI and OHCI drivers work okay > if hcd->stop isn't invoked when hcd->start fails?) They should. > > That's it - nothing more, nothing about UHCI... shouldn't UHCI take over > > at this point? > > It should. But the log messages don't indicate which companion has been > asked to take over; is it the broken one at 0000:02:00.0 or the working > one at 0000:02:00.1? > > (David, could you add some debugging code to the EHCI driver to print out > the exact mapping from an EHCI port to the companion controller/port > whenever a handoff occurs?) That's implicit in some information that's already printed out during EHCI init. The EHCI driver doesn't actually know (or want to know!) which companion handles a given port. I don't know which VIA EHCI that is, but I think VIA always uses an "ordered" mapping of companion controllers. So that ports 1 and 2 go to the first companion, 3 and 4 to the second, and so on (at least with SouthBridge versions, which have six or more ports). - Dave ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
