libusb should offer a means of reset. I maintain a package for ArchLinux
called restmsmice (http://sourceforge.net/projects/resetmsmice) based on
libusb, that does essentially that, reset the usb port, albeit just of a
specific input device in this case a mouse, so the device will work
properly if dual booting with Windows. Source code could be helpful.

What distro / kernel are you using? Could also be a driver problem with
your USB ports since you are unmounting it.

--
Jeremy MountainJohnson
Jeremy.MountainJohnson at gmail.com


On Wed, Jan 30, 2013 at 11:11 AM, Max Shinn
<max at bernsteinforpresident.com>wrote:

> On 1/30/13, Erik Mitchell <erik.mitchell at gmail.com> wrote:
> > I've run into this problem a few times. When I plug in a USB mass
> > storage device, such as my Kindle or my iPhone 4, it will show up as a
> > device and I can mount it, and everything is great.
> >
> > However, if I unmount it and unplug it, and then plug it in again, it
> > isn't detected by the USB system. I have tried different cables to no
> > avail.
>
> Does the same thing happen for normal flash drives, or just with
> devices?  I know my Maemo phone likes to do this every now and then
> for no apparent reason.
>
> -Max
> _______________________________________________
> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota
> tclug-list at mn-linux.org
> http://mailman.mn-linux.org/mailman/listinfo/tclug-list
>
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