#12178 NORM Future : Improve XO-1.5 wireless power handling

Zarro Boogs per Child bugtracker at laptop.org
Fri Oct 12 17:19:38 EDT 2012

#12178: Improve XO-1.5 wireless power handling
 Reporter:  dsd     |                 Owner:                
     Type:  defect  |                Status:  new           
 Priority:  normal  |             Milestone:  Future Release
Component:  kernel  |               Version:  not specified 
 Keywords:          |           Next_action:  never set     
 Verified:  0       |   Deployment_affected:                
Blockedby:          |              Blocking:                
 Setting the MMC_CAP_POWER_OFF_CARD flag on the host will result in power
 being removed to the wifi SDIO card when the network interface is brought
 down in Linux (the libertas driver has integration with runtime power

 Setting this on XO-1.5 seems reliable, so we may just need to tweak the
 kernel to set the flag when our hardware is detected in some upstream-
 acceptable fashion.

 However, I have my doubts if we are really powering down the card,
  # Everyone else seems to have trouble reliably powering up and down the
  # When the card comes back up, the driver detects the firmware is already
 present so it doesn't load the firmware again

 We may also need to fix "everyone elses problem" as part of the solution
 to #12177, meaning the quirking challenge would go away (since
 MMC_CAP_POWER_OFF_CARD could then be enabled by default for all users).

 Also, this could do with some wider testing; my notes suggest that I
 successfully ran a card power on/off loop overnight on one XO-1.5, but
 another XO-1.5 failed after 30 mins of the same loop.

Ticket URL: <http://dev.laptop.org/ticket/12178>
One Laptop Per Child <http://laptop.org/>
OLPC bug tracking system

More information about the Bugs mailing list