#6192 HIGH 8.2.0 (: Lid switch detection only works on AC

[Zarro Boogs per Child]

#6192: Lid switch detection only works on AC
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   Reporter:  cjb        |       Owner:  dilinger            
       Type:  defect     |      Status:  new                 
   Priority:  high       |   Milestone:  8.2.0 (was Update.2)
  Component:  kernel     |     Version:                      
 Resolution:             |    Keywords:  relnote             
Next_action:  never set  |    Verified:  0                   
  Blockedby:             |    Blocking:                      
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Comment(by wmb at firmworks.com):

 Experiments with OFW suggest that the 5536 often reports that an SCI event
 occurred after wakeup, even though the scope shows that no such event
 actually happened.

 I can't find any way to fix that in hardware.  Consequently, it would be
 prudent to change the kernel to recognize a lid wakeup properly, even if
 it is coincident with a spurious SCI event report.

 My test procedure:

 a) Connect a scope to SCI# (e.g. low side of R201).

 b) Set scope to trigger on falling edge, threshold 3.0V  (signal high/idle
 level is ~3.3V)

 c) Disconnect AC, powering XO from battery only

 d) Boot to ok prompt.

 e) Observe that SCI# pulses low every now and then, indicating 1% changes
 in battery charge

 f) lid-wakeup    \ Add the lid switch to the list of wakeup events

 h) ok  -1 18 acpi-l!    \ This clears any leftover wakeup event status
 bits

 i) Set scope to "one-shot trigger"

 j) ok  s

 k) Wave a magnet near the lid switch (by the mic light) to wakeup

 l) ok  18 acpi-l@ dup .  18 acpi-l!

 m) Observe that the value is c0000000 - the 80000000 bit indicates SCI,
 40000000 is lid

 n) Repeat i-m until you see a case where the scope did not trigger, but
 the value was still c0000000.  In my setup, it happens pretty much every
 time (the c0000000 happens every time, and most of the time, there is no
 actual SCI event.  Real SCI events only occur when a battery charge state
 report coincides with the test.)

-- 
Ticket URL: <http://dev.laptop.org/ticket/6192#comment:9>
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