#1423 HIGH BTest-4: USB power managment.

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#1423: USB power managment.
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  Reporter:  jg      |       Owner:  marcelo
      Type:  defect  |      Status:  new    
  Priority:  high    |   Milestone:  BTest-4
 Component:  kernel  |     Version:         
Resolution:          |    Keywords:  power  
  Verified:  0       |  
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Old description:

> This bug is to track issues pertaining to USB power management. First, we
> need to confirm that our USB class drivers work properly. Marcelo was
> working on the stack a while back.
>
> This is an active area of Linux development at the moment, so it will
> likely need continual reverification in the tinderbox.
>
> Arguably, this may need to interact with a power manager daemon, to set
> policy as to whether the system should suspend.
>
> And how USB devices that can suspend should deal with our fast
> suspend/resume is anyone's guess.

New description:

 This bug is to track issues pertaining to USB power management. First, we
 need to confirm that our USB class drivers work properly. Marcelo was
 working on the stack a while back.

 This is an active area of Linux development at the moment, so it will
 likely need continual reverification in the tinderbox.

 Arguably, this may need to interact with a power manager daemon, to set
 policy as to whether the system should suspend.

 And how USB devices that can suspend should deal with our fast
 suspend/resume is anyone's guess.

 Its not clear yet on just how to measure this.  USB +5 is switched by U56
 and there is not a sense resistor there.  One possibility is to break the
 line at the +5V regulator @ L28 and then do subtract out the current
 across R397.  That would give you whats happening on USB.  We could take a
 baseline with no USB devices plugged in and subtract out that as well.

Comment (by rsmith):

 Replying to [ticket:1423 jg]:
 > This bug is to track issues pertaining to USB power management. First,
 we need to confirm that our USB class drivers work properly. Marcelo was
 working on the stack a while back.
 >
 > This is an active area of Linux development at the moment, so it will
 likely need continual reverification in the tinderbox.
 >
 > Arguably, this may need to interact with a power manager daemon, to set
 policy as to whether the system should suspend.
 >
 > And how USB devices that can suspend should deal with our fast
 suspend/resume is anyone's guess.
 >

-- 
Ticket URL: <http://dev.laptop.org/ticket/1423#comment:4>
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