Regarding Wake On USB input from S3 Sleep

[Hans Petter Selasky]

On 02/14/16 09:48, Ian Smith wrote:
> On Sat, 13 Feb 2016 11:17:31 -0800, Luke wrote:
>   > > I searched the wiki on 'USB power' but noticed only sections 4 and 10 of
>   > > https://wiki.freebsd.org/TuningPowerConsumption seemed to relate at all.
>   > > If that's it or not, I'd appreciate some more guidance ..
>
>   > That's correct, section 10 from that wiki page.
>   > Here's all I did:
>   >
>   > $ sudo usbconfig
>   > (it then lists all USB related devices)
>   > $ sudo usbconfig -d 1.3 power_save
>   > (then put a device into powersave mode. I put this in a script)
>   >
>   > and that was it for me. The zenbook almost imediately reports an extra
>   > hour of battery and I can confirm it does indeed extend it's life to
>   > close to an hour.
>
> Ah, right.  Mine (6 uhci and 2 ehci root hubs) are all already in
> pwr=SAVE mode, except for the so far unused webcam:
>
> ugen3.2: <product 0x480c Chicony Electronics Co., Ltd.> at usbus3, cfg=0
> md=HOST spd=HIGH (480Mbps) pwr=ON (100mA)
>
> Setting that to power_save saved about 150mW, or 30mA at 5V.  Only a few
> extra minutes (~2%) of battery life, but every little bit helps, thanks.
>
> Not that that's really anything to do with the $subject ..
>

Hi,

By default our USB stack only enables power save for USB HUBs, because 
it assumes that non-USB HUB device, might be broken with regard to 
suspend. Your findings make sense.

--HPS