On Fri, 7 Jan 2005, David Brownell wrote: > > > Given that the UHCI LEGSUP register changed (a BIOS thing), I think > > > the first thing to try is making the UHCI driver get the port back > > > from the BIOS. It's very possible that changing that UHCI register > > > will automatically restore the correct PORT_OWNER setting. > > > > You think so? I'm a little doubtful that writing a UHCI configuration > > space register will cause a change to an EHCI port status bit, but who > > knows... > > Writing to that UHCI register is already futzing with > the PS/2 port controller (i8042). I find that more > implausible than seeing it futz with a USB register! :)
Hey, I just took another look at the UHCI spec. It turns out that bits 8-11 in the LEGSUP register are R/WC, not R/W. This means that the value 0x2f00 observed by Oliver is normal -- those bits simply were never cleared. Probably the value was 0x2f00 even before the suspend. It doesn't indicate any interference by the BIOS; or if there was interference, the BIOS returned control to Linux before the resume finished up. So there's no point worrying about that register. The problem must lie somewhere else. Maybe the hardware (not the BIOS) clears the PORT_OWNER bit during suspend/resume. Oliver, what happens if you run with CONFIG_USB_SUSPEND not set and apply the patch I wrote for Paul Ionescu in http://marc.theaimsgroup.com/?l=linux-usb-devel&m=110503079717138&w=2 ? It may help solve the "catastrophic" failure of usbcore you observed in http://marc.theaimsgroup.com/?l=linux-usb-devel&m=110487287514963&w=2 Interestingly, that log shows that with CONFIG_USB_SUSPEND unset, ehci-hcd did observe a connect-change event when the flip-flop changed, whereas the earlier log in http://marc.theaimsgroup.com/?l=linux-usb-devel&m=110486714720587&w=2 shows that with CONFIG_USB_SUSPEND set the driver did not observe such an event. Not until Oliver replugged the mouse. I don't know what this means, if anything, but it might be a clue. 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
