[Sugar-devel] Patch: Mobile dongles

[forster at ozonline.com.au]

Paul

Keeping the dongle powered also happens with automatic power management on the 1.75 (ie 15 seconds with no input). Same problem though, keyboard or trackpad input to wake up powers down the dongle.

It takes 35 seconds for the dongle to appear in the frame, then user input is required, more waiting, a total time of 65 seconds to make a connection.

The Huawei is rated at <= 500mA or 2.5W. That is presumably a peak rating, it is slightly warm to touch, my guess 1W or a little less average. I think not worth keeping powered during power switch initiated sleep.

You say "the hardware control is all or none' I took that to mean all 3 USB ports, but in suspend, it has the memory stick light out but the dongle light on. (the light may respond to data as well as power).

There is a case for powering the USB ports whenever a USB device is connected (automatic power management suspend not power switch initated sleep), it is impossible to know the characteristics of every USB device and whether they will recover gracefully to power interuption. If the user wanted best battery life they wouldnt leave a power hungry USB device plugged in.

Tony

> forster at ozonline.com.au wrote:
>  > Paul
>  > 
>  > Tried this with a XO-1.75 and a XO-1.5 both running OS31
>  > Tried a Huawei mobile dongle, a memory stick and a mouse
>  > 
>  > The only case where a USB device remains powered during sleep is the mobile 
>  > dongle on the 1.75
> 
> 
> huh.  okay, well, 1.75 is the first of the XO models that has the
> ability to leave the USB ports powered (and i assume they all do when
> the mobile dongle is used - the hardware control is all or none).  i
> guess that driver is talking to the USB stack somehow to accomplish
> this.
> 
> next question:  is this the right behavior?  if the dongle weren't
> power cycled during resume, i guess that might be a good thing?
> 
> paul
> 
>  > 
>  > Tony
>  > 
>  > > forster at ozonline.com.au wrote:
>  > >  > Thanks
>  > >  > 
>  > >  > I have noticed another issue with the mobile dongle.  OS31, XO-1.75
>  > >  > Press the power button once and wait for sleep.  The dongle remains
>  > > 
>  > > this is very surprising.  do other USB devices remain powered when the
>  > > laptop sleeps?  we've done nothing intentional to change this (or fix this,
>  > > depending on your point of view :-) in this release. 
>  > > 
>  > > paul
>  > > 
>  > >  > powered on (which is a good or bad thing depending on your point of
>  > >  > view), then press the power button to wake the laptop, the dongle
>  > >  > is briefly turned off and the connection is lost, negating any
>  > >  > benefit from keeping it powered during sleep.
>  > >  > 
>  > >  > Tony
>  > >  > 
>  > > =---------------------
>  > >  paul fox, pgf at laptop.org
>  > > _______________________________________________
>  > > Sugar-devel mailing list
>  > > Sugar-devel at lists.sugarlabs.org
>  > > http://lists.sugarlabs.org/listinfo/sugar-devel
>  > > 
>  > > _____________________________________________________
>  > > This mail has been virus scanned by Australia On Line
>  > > see http://www.australiaonline.net.au/mailscanning
> 
> =---------------------
>  paul fox, pgf at laptop.org
> 
> _____________________________________________________
> This mail has been virus scanned by Australia On Line
> see http://www.australiaonline.net.au/mailscanning