On Fri, 3 Jul 2009, David Brownell wrote: > On Friday 03 July 2009, Pierre Ossman wrote: > > Is there any way I can force > > the bus to power down and up again to simulate removal and reinsertion? > > As Alan noted -- not really. Maybe hook it up to an external > hub; most of those seem to claim they support power switching. > > I did once have a system with an OHCI root hub which supported > power switching. Which was handy because one UPS needed to > start its enumeration from link-power-off, not unlike what you > are observing. > > That system made a good regression test for the feature in the > Linux-USB stack whereby it tried to force root hub enumeration > to start from power-off. Since that system died a while back > (sigh), I no longer know if that still works on those fortunate > systems which *do* support such switching. If you have any external hubs that support port-power switching, they should make equally good test cases. After all, Linux doesn't make much distinction between root hub and external hub enumeration. 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
