Openmoko Bug #1597: after a long suspend time, kernel thread events/0 sits eating 30% cpu

[Openmoko Public Trac]

#1597: after a long suspend time, kernel thread events/0 sits eating 30% cpu
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    Reporter:  raster           |        Owner:  zecke     
        Type:  defect           |       Status:  in_testing
    Priority:  normal           |    Milestone:            
   Component:  System Software  |      Version:            
    Severity:  major            |   Resolution:            
    Keywords:                   |    Blockedby:            
Reproducible:                   |     Blocking:            
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Comment(by werner):

 Just had a device running FSO MS3 do something that looked similar: about
 75% Xglamo, 15% events/0, 5% SDIO Helper. I don't think FSO MS3 ever
 suspends, so this doesn't seem to be related to suspend/resume problems.

 In terms of events actually reported through /dev/input/event*, I only saw
 the accelerometers, pumping out data at about 400kHz. Brutally forcing
 their
 interrupts off (gpio f0=1 g8=1 - warning, that's CPU GPIO output driving
 against interrupt output of the acceleration sensors) made them stop but
 didn't slow down events/0.

 Killing Xglamo also had no effect on events/0. However it's interesting to
 note that the CPU load of events/0 did not increase.

 Note that, after stopping the acceleration sensors from reporting data,
 there was no other significant amount of data coming out of
 /dev/input/event*.

 Killing virtually all other processes on the system had no effect on
 events/0.

 Throwing a crowbar into SDIO (by disabling the SD clock, gpio e5=0) did
 stop
 SDIO Helper and events/0 from running wild. Unfortunately, the Atheros
 SDIO
 stack does not recover when I re-enable the clock.

-- 
Ticket URL: <https://docs.openmoko.org/trac/ticket/1597#comment:33>
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