#12657 NORM 13.2.0: Fix btmrvl/mwifiex suspend interactions

[Zarro Boogs per Child]

#12657: Fix btmrvl/mwifiex suspend interactions
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           Reporter:  dsd            |       Owner:  pgf          
               Type:  defect         |      Status:  new          
           Priority:  normal         |   Milestone:  13.2.0       
          Component:  kernel         |     Version:  not specified
         Resolution:                 |    Keywords:               
        Next_action:  test in build  |    Verified:  0            
Deployment_affected:                 |   Blockedby:               
           Blocking:                 |  
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Comment(by pgf):

 if either driver wishes the card to remain powered across suspend,
 then the hang does not occur.

 if we enable the no_console_suspend kernel commandline parameter,
 then the hang does not occur.

 when the hang occurs, it happens inside of:
     - bus_remove_device(), called from
     - device_del(), called from
     - sdio_remove_func(), called from
     - mmc_sdio_remove(), called from
     - mmc_suspend_host() after mmc_sdio_suspend() has returned -ENOSYS

 the OLPC copy of mmc_suspend_host() has been modified
 to return -ENOSYS if no card function has requested power be maintained.

 i'd provide a "real" stack backtrace, except for the issue of the problem
 not reproducing if no_console_suspend is enabled.

 it's clear that there's mismanagement of devices happening somewhere.

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Ticket URL: <http://dev.laptop.org/ticket/12657#comment:3>
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