#2765 HIGH Trial-3: EC needs programmable delay to turn off DCON chip.

[Zarro Boogs per Child]

#2765: EC needs programmable delay to turn off DCON chip.
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  Reporter:  jg                   |       Owner:  David.Lin
      Type:  defect               |      Status:  new      
  Priority:  high                 |   Milestone:  Trial-3  
 Component:  embedded controller  |     Version:           
Resolution:                       |    Keywords:  power    
  Verified:  0                    |  
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Changes (by rsmith):

 * cc: rsmith (added)

Comment:

 Replying to [comment:2 jg]:
 > David, I need to be able to set a time at which the DCON will be turned
 off.  Otherwise, I have to wake the system up just to turn off the screen,
 which is complicated and messy.
 >

 Some questions I have:

 What do you want to use to reset the timeout?  Key/touch pad activity and
 the Game Keys or when the host wakes up and processes a command and thus
 does EC activity.

 What is this timeout measured in seconds? Minutes?  Whats the default?

 The kernel need to sprout knowledge of DCON init.  Whats the mechanism for
 the kernel to discover that the dcon has been powered down and that it
 needs to re-enable it?  I don't think you want the kernel to re-do the
 init every wakeup so the kernel will either have to query the EC on wakeup
 for this info or keep its own timer and state info.

 There are some generic things like power up time here to consider as well.
 I don't know how long it takes the dcon to stabilize after you power it
 on.  Can we properly detect dcon command failure in the kernel and know
 that we have/have not re-established dcon init 100% correctly?

 I'm not so sure that the EC doing this on its own is going to be that much
 cleaner than just waking up the kernel via an RTC to do it.  Turning off
 is the easy part.

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Ticket URL: <https://dev.laptop.org/ticket/2765#comment:3>
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