On Sun, 2009-03-08 at 12:58 -0400, Alan Stern wrote: > On Sun, 8 Mar 2009, Maxim Levitsky wrote: > > > > No, adding a dependency won't work because it is valid to load > > > uhci-hcd without ehci-hcd. The only time a problem occurs is if you > > > load both of them in the wrong order. (And in fact it's pretty rare > > > for that to cause a real problem -- mostly you just get some annoying > > > messages in the log.) > > But since it can cause a problem, this has to be somehow automatically > > fixed isn't it? > > Can it cause a problem? I'm not so sure -- it depends on what you mean > by "problem". One person complained forcefully just because he didn't > like all the extra "disconnect" messages in the system log, even though > everything worked perfectly. > > > For example how to I ensure the correct order with udev? > > You can't. But you can add rules to /etc/modprobe.conf to insure that > ehci-hcd is always loaded before uhci-hcd. > > > > CONFIG_USB_EHCI_ROOT_HUB_TT shouldn't make any difference at all. > > > That setting matters only for hardware using the ARC/TDI design, which > > > is not present in your Intel chipset. Likewise, provided ehci-hcd is > > > loaded first, it shouldn't make any difference whether uhci-hcd is > > > loaded or not. > > Well, I retest this. > > But it seems to work > > Best would be if you could send two usbmon traces, one showing the > problem and one showing what happens when uhci-hcd isn't loaded but > everything else is the same. For each test, plug in the printer's USB > cable after starting the trace. Will do soon. > > And don't try to confuse matters by querying the printer status while > reloading its firmware. Well, I suspected that there is some concurrent access from both usb drivers, so I tried all options to crash it.... > Alan Stern > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
