#12494 HIGH 13.1.0: mwifiex loses wifi upon suspend/resume

Zarro Boogs per Child bugtracker at laptop.org
Wed Jan 23 21:55:35 EST 2013

#12494: mwifiex loses wifi upon suspend/resume
           Reporter:  jvonau     |       Owner:  shep                              
               Type:  defect     |      Status:  new                               
           Priority:  high       |   Milestone:  13.1.0                            
          Component:  kernel     |     Version:  Development source as of this date
         Resolution:             |    Keywords:                                    
        Next_action:  never set  |    Verified:  0                                 
Deployment_affected:  AU         |   Blockedby:                                    
           Blocking:             |  

Comment(by wad):

 This has been tracked to a problem with the power supply to the WLAN card.
 If the 8787 is associated with an access point which support the new low
 power WiFi mode, it will automatically enter a low power mode.   If power
 is dropped during suspend (while the card is in this low power mode), it
 will take a very long time (tens of seconds) for the power to drop.   If
 resumed before the power has dropped, the card is not properly reset and
 the driver can't talk to it.

 We are looking into multiple solutions for this, one being the addition of
 a hardware power discharge circuit and the other being testing of the
 WLAN_RESET# signal.

 There is likely to be a related problem with the 8686 card, once we enable
 its use of low power mode.

Ticket URL: <http://dev.laptop.org/ticket/12494#comment:3>
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