#9449 NORM 1.5-CTe: Laptop reboots on first resume

[Zarro Boogs per Child]

#9449: Laptop reboots on first resume
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           Reporter:  wad           |       Owner:  wad          
               Type:  defect        |      Status:  new          
           Priority:  normal        |   Milestone:  1.5-CTest    
          Component:  not assigned  |     Version:  not specified
         Resolution:                |    Keywords:               
        Next_action:  diagnose      |    Verified:  1            
Deployment_affected:                |   Blockedby:               
           Blocking:                |  
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Comment(by wmb at firmworks.com):

 The fix reflected in q3a10e greatly reduces the failure frequency but does
 not eliminate it.  The syndrome of the less-frequent failures is slightly
 different - the memory is not completely dead, but has bit-rot.

 The remaining problem is that DMA activity from the USB sometimes kicks
 the RAMs out of self-refresh.  Turning off the USB controller seems to fix
 the problem.  My latest test OFW has run several hundred
 reboot/suspend/resume cycles without a resume reset.

 This explains why the failure only happened on the first suspend.  After
 that, the USB controller was off (OFW doesn't turn it back on after
 resume).

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Ticket URL: <http://dev.laptop.org/ticket/9449#comment:6>
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