#11570 HIGH 1.75-so: XO-1.75 kernel time drift over 24-hr runin with suspend resume

[Zarro Boogs per Child]

#11570: XO-1.75 kernel time drift over 24-hr runin with suspend resume
--------------------------------+-------------------------------------------
           Reporter:  Quozl     |       Owner:  dilinger                         
               Type:  defect    |      Status:  new                              
           Priority:  high      |   Milestone:  1.75-software                    
          Component:  kernel    |     Version:  Development build as of this date
         Resolution:            |    Keywords:                                   
        Next_action:  diagnose  |    Verified:  0                                
Deployment_affected:            |   Blockedby:                                   
           Blocking:            |  
--------------------------------+-------------------------------------------

Comment(by Quozl):

 No correspondence with SKU seen.

 ||''unit''||''time after runin''||''ntp step time server offset''||
 ||XO-1.75 C1 SKU201||2012-01-29 22:18:34+00:00||6203 sec||
 ||XO-1.75 C1 SKU202||2012-01-30 00:11:04+00:00||-547 sec||
 ||XO-1.75 C1 SKU200||2012-01-30 00:15:35+00:00||-818 sec||
 ||XO-1.75 B1||2012-01-30 02:12:01+00:00||-7804 sec||
 ||XO-1.75 B4||2012-01-29 23:15:04+00:00||2814 sec||
 ||XO-1.75 B1||2012-01-30 00:30:37+00:00||-1718 sec||

 *''time after runin'' was a sample of the kernel time taken after 115
 hours of runin, at 2012-01-30 00:01:57+00:00,
 *the RTC of each unit was set using ''ntp-set-clock'' prior to the runin
 test,
 *''ntp step time server offset'' was the value shown by ''ntpdate
 pool.ntp.org''.
 *kernel used was be5c532a - arm-3.0-wip.

 Current design: at boot, the RTC is used to set the kernel time.  The
 kernel maintains this while running.  On controlled shutdown or reboot,
 the kernel time is written to the RTC.

 Therefore, observations of drift of the RTC will include drift of the
 kernel time, if the kernel is run and a controlled shutdown or reboot
 occurs.

-- 
Ticket URL: <http://dev.laptop.org/ticket/11570#comment:3>
One Laptop Per Child <http://laptop.org/>
OLPC bug tracking system