On Thu, 6 Jan 2005, David Brownell wrote: > On Thursday 06 January 2005 1:01 pm, Alan Stern wrote: > > > > If the power was shut off entirely, upon resume the controller would have > > seen a connect change event. No such event shows up in the system logs > > you posted with ehci-hcd unloaded. But it does show up in the logs with > > ehci-hcd loaded. > > BIOS may have swallowed that event on behalf of UHCI ... > so that the only way UHCI will see it is if it does a > complete reset, including grabbing control of the HC > back from the BIOS.
If power was truly lost and the connect-change event swallowed, the mouse itself would need to be enumerated and initialized over again (unless the BIOS had initialized it to the same address and state as Linux did). But it worked when Oliver tried using it. Doing a complete reset would _force_ connect change events on every port, even when they aren't needed. I don't think that's a good idea. And merely grabbing the HC back from the BIOS would not cause the events. But the driver _could_ check to see if BIOS had taken control, and if it had then grab the HC back and reset it. Alan Stern ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
