#12216 NORM 13.1.0: XO-1.75/XO4 don't support 1.8 volt SD cards

Zarro Boogs per Child bugtracker at laptop.org
Sun Dec 2 11:31:42 EST 2012

#12216: XO-1.75/XO4 don't support 1.8 volt SD cards
           Reporter:  jvonau        |       Owner:  cjb                     
               Type:  defect        |      Status:  assigned                
           Priority:  normal        |   Milestone:  13.1.0                  
          Component:  kernel        |     Version:  Software Build 12.1.0-21
         Resolution:                |    Keywords:                          
        Next_action:  add to build  |    Verified:  0                       
Deployment_affected:                |   Blockedby:                          
           Blocking:                |  
Changes (by dsd):

  * next_action:  never set => add to build


 Thanks for the explanation - that clears it up.

 For the upstream XO-1.75 fix, we seem to have settled on simply providing
 a flag in the device tree that indicates that the controller has no 1.8v
 supply available. So there is no immediate need for the new EC command,
 although it would be useful to have around. It was also valuable to be
 able to verify what we were suspecting.

 The upstream patches have been tentatively acked by cjb:

  * [http://marc.info/?l=linux-mmc&m=135386696513353&w=2 sdhci: add quirk
 for lack of 1.8v support]
  * [http://marc.info/?l=linux-mmc&m=135386696513354&w=2 mmc: add no-1-8-v
 device tree flag]

 With the upstream path seemingly complete, I've added a hack to
 arm-3.0-wip to disable 1.8v and this makes George Hunt's UHS-I card work

Ticket URL: <http://dev.laptop.org/ticket/12216#comment:18>
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