> Could a control endpoint timeout in general imply that the parent High > Speed HUB, if any, should be reset?
Yes, I think so. Sadly, there's no way to query whether a TT is jammed or not. So my heuristic is that when a clear-stall transaction fails with a timeout, and it's to a full-speed device with a high-speed hub, to reset the TT. Resetting the TT will cause every other device using it to require require a clear-stall sequence, but that's not a big problem. We see hub wedging problems multiple times per hour. because this system has a long cable from the host to hub, and there are frequent static discharges nearby. I've been testing with a static discharge simulator that hits the cables with nanosecond kilovolt pulses and it's made it much easier to reproduce the problems. So I can probably propose a set of patches in the next week or so. On Thu, May 5, 2011 at 1:09 AM, Hans Petter Selasky <[email protected]>wrote: > On Thursday 05 May 2011 09:15:09 Trevor Blackwell wrote: > > 8.2-STABLE. I'm willing to run whatever. > > > > I suspect the problem I'm having is the same as this: > > http://kerneltrap.org/mailarchive/linux-usb/2009/5/15/5761363 > > > > I can manually kick it out of the wedged state by sending a RESET_TT > > transaction to the hub with usbconfig -d ugen1.3 do_request 0x23 0x09 > > 0x0000 0x0001 0 > > > > (UT_WRITE_CLASS_OTHER, UR_RESET_TT) > > > > I'm working on adding code to do this. My current hack is to do it from > > uhub_explore. When my driver tries to do a clear-stall and gets a timeout > > error from the clear-stall, it sets a flag on the parent_hs_hub to > request > > a RESET_TT. uhub_explore notices the flag and does it. > > > > Possibly I could also add it to usb_do_clear_stall_callback, but I don't > > think I can call usb_do_request from inside a callback. > > > > Any suggestions? > > Hi, > > I think it is best to do this from the root HUB thread, then the operation > gets properly serialised. Then the clear-stalls requests will simply be > pending until normal operation is established. > > > --HPS > -- Trevor Blackwell [email protected] 650 776 7870 _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "[email protected]"
