#9008 NORM 8.2.1: touchpad suddenly stops working (recalibration failed)

Zarro Boogs per Child bugtracker at laptop.org
Thu Apr 23 18:17:44 EDT 2009

#9008: touchpad suddenly stops working (recalibration failed)
           Reporter:  HoboPrimate  |       Owner:  dsaxena      
               Type:  defect       |      Status:  closed       
           Priority:  normal       |   Milestone:  8.2.1        
          Component:  kernel       |     Version:  not specified
         Resolution:  fixed        |    Keywords:  cjbfor9.1.0  
        Next_action:  finalize     |    Verified:  0            
Deployment_affected:               |   Blockedby:               
           Blocking:               |  
Changes (by pgf):

  * status:  new => closed
  * resolution:  => fixed


 we now understand this bug.  it was a regression, introduced at
 approximately q2e16, when the EC firmware was modified with code from
 quanta to support the new keyboard controller.  that code contained a
 register change which "adds a 16us delay on some parts of the ps2 protocol
 and was screwing up the reception of 0xfa (acks) from the touchpad".
 (that's a quote from richard's commit for the fix, which was introduced in

 the OLPC kernel tree has a workaround for the recalibration failed issue
 in the form of forced retries.  that workaround is not upstream, but it
 now doesn't seem that it needs to be, given the firmware fix.

Ticket URL: <http://dev.laptop.org/ticket/9008#comment:16>
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