#4470 BLOC Update.: WLAN stops working after good functionality

[Zarro Boogs per Child]

#4470: WLAN stops working after good functionality
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  Reporter:  kimquirk  |       Owner:  dwmw2   
      Type:  defect    |      Status:  new     
  Priority:  blocker   |   Milestone:  Update.1
 Component:  wireless  |     Version:          
Resolution:            |    Keywords:          
  Verified:  1         |  
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Comment(by dwmw2):

 It is expected that you cannot reproduce with a C2 machine and current
 software/firmware.

 I believe there were three independent causes for these symptoms. Firstly,
 the command queueing in the driver was broken and would get into a state
 where it never attempted to submit new commands. This is kind of fixed
 now, and a more complete rearchitecture of the command queueing in the
 driver is pending.

 Secondly, there was the firmware bug which was fixed in 5.110.20.p2, which
 first caused the lack of response to the scan command, and then caused
 further USB TX transactions to fail completely.

 Finally, in unmodified C1 and earlier hardware the power rails are very
 noisy, and turning the screen on and off sometimes seems to crash the
 wireless firmware in a fashion indistinguishable from the above --
 transmission on USB just breaks, while reception is still working fine.
 Since other misbehaviour on these machines includes reboots and complete
 crashes when we turn the screen off and on, I don't think it makes sense
 to care too deeply about this particular manifestation of the problem.

 So I believe the 5.110.20.p2 firmware is good. Waiting on Kim's testing on
 a wider sample of C2 machines, before we close the bug.

-- 
Ticket URL: <http://dev.laptop.org/ticket/4470#comment:77>
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