I'm copying this to the linux-usb-devel mailing list for you, because other people on that mailing list know more about how the EHCI driver works than I do. For those interested, the thread starts with
http://marc.theaimsgroup.com/?l=linux-usb-users&m=108974899223967&w=2 Alan Stern On Wed, 14 Jul 2004, Daniel Miller (IMI) wrote: > Well I ran overnight and crashed the box again, ant the Alt-SysRq keys > didn't work. I'd tested before the crash and they were working then (so I > know I turned SysRq on correctly). Apparently it's too hard-crashed for > that. I already knew that logging in via network didn't work after the > crash. > > One thing that I've noticed (now that I have *two* whole sample points) is > that during normal, successful detection, the syslog messages that I see > (among many others) are: > > Jul 13 18:57:06 M7600M12 kernel: hub.c: port 3, portstatus 511, change 0, > 480 Mb/s > Jul 13 18:57:06 M7600M12 kernel: hub.c: port 3 of hub 1 not reset yet, > waiting 10ms > Jul 13 18:57:06 M7600M12 kernel: hub.c: port 3, portstatus 511, change 0, > 480 Mb/s > Jul 13 18:57:06 M7600M12 kernel: hub.c: port 3 of hub 1 not reset yet, > waiting 10ms > Jul 13 18:57:06 M7600M12 kernel: ehci_hcd 01:0a.2: port 3 high speed > Jul 13 18:57:06 M7600M12 kernel: ehci_hcd 01:0a.2: GetStatus port 3 status > 001005 POWER sig=se0 PE CONNECT > > Note the messages from ehci_hcd... when the unit crashes, however, the last > messages that I see are the "hub not reset" messages from hub.c. That *may* > suggest that the crash is occuring in ehci_hcd... I'll research this > further; at this point, I don't know if ehci_hcd is invoked from usbcore > (hub.c), or if they are somehow running independently... Both. In this case hub.c is polling ehci_hcd to read the port status at 10ms intervals. At the same time, ehci_hcd may be receiving interrupts that relate to various port events. > Also, I'll look into getting another box set up with kernel 2.6 again; as > usual in EngDev, we're short of hardware!! > > Dan Miller ------------------------------------------------------- This SF.Net email sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
