#7690 NORM 8.2.0 (: msh0 device does not come back up (nor NM/Sugar notified once it does) after power cycling radio via /sys/power/wlan_enabled

[Zarro Boogs per Child]

#7690: msh0 device does not come back up (nor NM/Sugar notified once it does)
after power cycling radio via /sys/power/wlan_enabled
--------------------------+-------------------------------------------------
 Reporter:  mtd           |         Owner:                                   
     Type:  defect        |        Status:  new                              
 Priority:  normal        |     Milestone:  8.2.0 (was Update.2)             
Component:  not assigned  |       Version:  Development build as of this date
 Keywords:                |   Next_action:  diagnose                         
 Verified:  0             |     Blockedby:                                   
 Blocking:  6995          |  
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 Performing either of the following sequence of actions should result in,
 at worst, no other net effect than closing and opening the lid:

 1a) enable "Extreme Power Management" in the sugar-control-panel

 1b) disable "Extreme Power Management" in the sugar-control-panel

 or:

 {{{
 echo 0 > /sys/power/wlan_enabled
 echo 1 > /sys/power/wlan_enabled
 }}}

 Instead, what happens on my C2 XO with joyride-2174 is best explained by
 the attached typescript log of commands/output, in which I'm going to:

 - confirm the normal state of affairs

 - power cycle the radio

 - display the bad state of affairs

 - recover msh0, haldaemon and NM to the normal state of affairs

 Note that there seem to be two separate issues:

 1) haldaemon does not get notified about msh0 coming back up

 2) restarting any dbus service causes sugar to be unable to use those
 services (more exactly, the old handles are invalid, causing problems; and
 the new services are not used).

 Sugar (shell) is not in a great state after all these gyrations, as can be
 seen by the attached shell.log (neither the battery icon nor shutting down
 works, since we've lost haldaemon).

 I'm also attaching /var/log/messages in case it's of interest.

 This may be a blocker for 6995 if we want to have the "disconnect" items
 in the wireless and mesh icons shut down the radio, and the MeshBox bring
 it up - this functionality is tantalizingly close, were it not for this
 issue.

 I can see at least one workaround, but I think it's a decent-sized one -
 again, for the power gains, it might be justified:

 1) bring up the radio, do ifconfig msh0 up, and restart haldaemon and
 NetworkManager if, when the user switches to the Mesh/Neighborhood view:
 a) the radio is off; and b) the user hasn't enabled extreme power
 management (this step is completely doable)

 2) allow sugar to recover gracefully from losing its dbus handle to
 haldaemon (this might not be terrible)

-- 
Ticket URL: <http://dev.laptop.org/ticket/7690>
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