#6935 NORM Never A: Turn off USB?

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#6935: Turn off USB?
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 Reporter:  cjb     |       Owner:  rsmith        
     Type:  defect  |      Status:  new           
 Priority:  normal  |   Milestone:  Never Assigned
Component:  kernel  |     Version:                
 Keywords:  power   |    Verified:  0             
 Blocking:          |   Blockedby:                
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 I'm working on a manually-selected UI mode that does best possible efforts
 to preserve power.  It can be thought of as the "reading under the covers"
 mode that tries to prolong your battery while you're alone.  Namely, it
 would:

  * turn on automatic idle suspends
  * turn off networking
  * possibly use the camera to detect external lighting, and modify the
 backlight brightness according to how bright the environment is (turning
 it off altogether if you're outside).

 The "turn off networking" part won't gain us much at the moment, because
 even unloading the wireless module doesn't stop the power draw of the 8388
 -- we can't disable power to its rail altogether, because it's the main
 3.3V rail.  We should instead put it into reset for the duration of the
 low-power mode.

 Richard, please point us at the documentation for doing this (via the
 EC?).  Andres or Dave, please think about how userspace (with root) could
 ask for USB to be turned off completely until it wants to turn it back on
 again.  The rationale for dropping USB completely is that it lets us show
 how good our suspend/resume times will be once we have USB resume put in
 its place.  (Hey, it might also save power.)

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Ticket URL: <http://dev.laptop.org/ticket/6935>
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