#8667 HIGH 8.2.1: wpa_supplicant generates many redundant scan requests before associating

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#8667: wpa_supplicant generates many redundant scan requests before associating
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   Reporter:  jcardona  |       Owner:  dsaxena      
       Type:  defect    |      Status:  new          
   Priority:  high      |   Milestone:  8.2.1        
  Component:  wireless  |     Version:  not specified
 Resolution:            |    Keywords:               
Next_action:  package   |    Verified:  0            
  Blockedby:            |    Blocking:               
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Comment(by carrano):

 '''The bug behavior (scanning and association)'''

 I installed the
 [http://dev.laptop.org/~dsaxena/kernel-2.6.25-20080926.1.olpc.5f842a369c6d018.i586.rpm
 latest test kernel above] and concentrated on the scanning operations.
 Here are some pieces of the puzzle that were exhaustively tested and
 confirmed:

  * Whenever the association to my AP fails (GUI), an scanning in the
 command line, issued immediately after the assoc fail *will also fail*
 with "interface doesn't support scanning: network is down" (logs will be
 attached)

  * Successive scanning commands after a failed one will eventually work,
 with unknown reason

  * If a scanning is successful, successive attempts will *always* be
 successful UNLESS an attempt to associate to the AP is done, in which case
 the scanning will start failing again.

 Some logs for fail or success are attached in two tar balls to this
 ticket.

 This scanning issues partial state machine derived from the above (sorry
 for the not very formal representation):

  * If (previous scan was ok) and (action is scan) => scan succeeds
  * If (previous scan was ok) and (action is try to associate) => scan
 fails
  * If (previous scan failed) and (action is scan) => scan result is
 unknown but 5 times more likely to fail)

 '''The user experience'''
 In terms of user experience, the details for a failure are:

 1 - The user clicks on the AP icon, the GUI will either ask for a key or
 not (because it has it already)

 2 - The AP circle starts blinking and the keyhole led blinks fast for some
 seconds, remains off for a second, on for a second, and finally goes off
 definitely

 3 - Immediately after 2, the AP stops to blink, the association fails, the
 message "connecting" disappears and "connect" option shows up again.

-- 
Ticket URL: <http://dev.laptop.org/ticket/8667#comment:9>
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