On Tuesday 14 September 2004 8:10 am, Alan Stern wrote: > On Mon, 13 Sep 2004, David Brownell wrote: > > > The IRQ handler can't do much at all; it just got an IRQ that > > said the HC died. Resetting the controller is about all it can > > do (so it's in a known and "safe" state), other than notifying > > usbcore that it's cleanup-time. > > > > A more interesting question is whether usbcore should try > > to actually restart the HCD. Eventually that'd be nice to > > do, but for now the infrastructure seems lacking. So I'd > > be content to just see all devices get cleanly shut down. > > But what should happen to the root hub? It shouldn't be disconnected, > because the HCD will try to deregister it later on.
Root hub disconnect is all special cased anyway ... it could be done so that's not an issue. There's no parent hub, so what would it disconnect from? > Should it be left in > the CONFIGURED state or changed to the NOTATTACHED state? > Should the hub driver be unbound? Initially all that's important is that the root hub just be completely idled. > Or should the HCD's stop() routine be called, which > will deallocate everything associated with the root hub? (That would make > it easy to restart the HC later; just call the start() routine.) I thought about that at one point. But resume-from-poweroff cases also need to restart the HC ... stop()/start() isn't really necessary. (Though maybe only OHCI does that just now, and even that's only after serious struggles with pmcore code in 2.6, which doesn't like hot-unpluggable devices.) Also, automagic restarting wouldn't always be appropriate. It shouldn't continue forever, for one thing... :) > > Right now I'm > > trying to find out what's up with resume after suspend-to-disk, > > which is actually somewhat related (the root hub does get > > reset), but other than pmcore problems I think the main issue > > is root hub timers not getting restarted right. > > This gets into that whole tricky area of power-off resets we discussed in > the spring. Are usb_devices supposed to be preserved across > suspend-to-disk? Nope, since they all get powered off. If the pmcore code worked sanely, we'd already be disconnecting every USB device on those paths. - Dave ------------------------------------------------------- This SF.Net email is sponsored by: thawte's Crypto Challenge Vl Crack the code and win a Sony DCRHC40 MiniDV Digital Handycam Camcorder. More prizes in the weekly Lunch Hour Challenge. Sign up NOW http://ad.doubleclick.net/clk;10740251;10262165;m _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
