Re: USB devices fail unnecessarily on unpowered hubs

[David Liontooth <liontooth@cogweb.net>]

Alan Stern wrote:
> Trying to draw too much current from an unpowered hub can and does cause 
> data loss.
>   
I consider this issue closed; thank you for looking at it. The
workaround is reasonably simple for the common situation of mounting a
USB stick on a keyboard, perhaps with a mouse attached in a second port:

NUM="$(dmesg | tail -n 3 | grep -r 'new full speed USB device' | cut -b
5-9)"
echo -n 1 >/sys/bus/usb/devices/$NUM/bConfigurationValue

with the understanding this breaks USB power rules and can lead to data
loss.

Dave