On Fri, 3 Jun 2005, Stuart MacDonald wrote: > From: Alan Stern [mailto:[EMAIL PROTECTED] > > However, there is one possibility... Older Intel UHCI > > hardware (the PIIX3 > > Neptune chipset) has an erratum that causes the controller > > sometimes to > > update a completed TD's status but not update the QH's > > element pointer. > > As a result the controller remains stuck on the completed TD and never > > advances to the next one. Could that be happening to you? > > You can find > > out by building the driver with CONFIG_USB_DEBUG turned on > > and loading it > > with > > > > modprobe uhci debug=3 > > > > Then the file under /proc/driver/uhci/ corresponding to the > > controller in > > use will contain debugging information showing the current > > state of the > > schedule. If you examine that while the queue is stopped > > you'll be able > > to see exactly what's wrong. > > Hm, interesting. I posted this a few days ago, but here it is again; > the output of /proc/driver/uhci/hc0 when the queueing breaks. I don't > think I had debug turned on at the time though. > > Also attached below is the debug=3 version. I don't think the errata > is the cause though; if I read that right the TDs are all still > active.
The debugging files make it clear; the erratum I mentioned is _not_ the problem. Rather, the schedules themselves are messed up. That's got to be an error in the controller driver. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by: NEC IT Guy Games. How far can you shotput a projector? How fast can you ride your desk chair down the office luge track? If you want to score the big prize, get to know the little guy. Play to win an NEC 61" plasma display: http://www.necitguy.com/?r=20 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
