power off 5V on USB port

[Julian H. Stacey]

Hi Matthias & usb@
Matthias Apitz wrote:
> Hello,
> 
> I'm using an Ubuntu smartphone connected on one of the USB ports to my
> netbook as a router to the Internet. I wanted to power-off the USB port to
> a) save energy in the netbook and
> b) not having the phone always charged for the memory effect in the battery.
> 
> I tried:
> 
> $ usbconfig
> ...
> ugen0.3: <AquarisE4.5 BQ> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA)
> 
> # usbconfig -d ugen0.3 power_off
> # usbconfig -d ugen0.3 
> ugen0.3: <AquarisE4.5 BQ> at usbus0, cfg=255 md=HOST spd=HIGH (480Mbps) pwr=OFF (500mA)
> 
> as you can see the state is now pwr=OFF, but in this state the USB port
> is not longer usable. What is the correct way to shutdown the 5V
> provided via USB to the device?
> 
> Thanks
> 
> 	matthias

I assume you'd prefer a software solution, but maybe there's a
hardware solutions too. Here's an extract of a mail to a friend:

] I bought a short USB (2) OTG cable for my phone, 
] 
]  http://www.conrad.de/ce/de/product/986693/USB-20-Anschlusskabel-1x-USB-20-Stecker-Micro-B-1x-USB-20-Buchse-A-010-m-Schwarz-mit-OTG-Funktion-vergoldete-St
] Translation:
]  https://translate.google.com/translate?sl=de&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.conrad.de%2Fce%2Fde%2Fproduct%2F986693%2FUSB-20-Anschlusskabel-1x-USB-20-Stecker-Micro-B-1x-USB-20-Buchse-A-010-m-Schwarz-mit-OTG-Funktion-vergoldete-St&edit-text=
] 
] It works for data, allows phone to access USB sticks & via
] an SDHC adapter those cards too.  Cost 7 Euro.
] 
] Curiously, it fails to charge phone, maybe there's a reason for that here:
]  http://en.wikipedia.org/wiki/USB_On-The-Go

Cheers,
Julian
--
Julian Stacey, BSD Linux Unix C Sys Eng Consultant Munich http://berklix.com
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