#11471 HIGH 1.75-so: Crash in mmp2_pcm_open and related code

Zarro Boogs per Child bugtracker at laptop.org
Sun Dec 4 14:25:58 EST 2011

#11471: Crash in mmp2_pcm_open and related code
           Reporter:  greenfeld  |       Owner:  saadia                           
               Type:  defect     |      Status:  new                              
           Priority:  high       |   Milestone:  1.75-software                    
          Component:  kernel     |     Version:  Development build as of this date
         Resolution:             |    Keywords:                                   
        Next_action:  diagnose   |    Verified:  0                                
Deployment_affected:             |   Blockedby:                                   
           Blocking:             |  

Comment(by corbet):

 Two branches can now be found at git://git.lwn.net/linux-2.6.git

 arm-3.0-wip-adma1 reverts the 32K hack and simply instantiates the second
 audio device.

 arm-3.0-wip-adma2, instead, puts a hack into the XO 1.75 initialization
 code to just step on the second device and force it to be quiet.

 Either approach makes the spurious interrupt problem go away.  My belief
 is that -adma1 is the better fix, assuming that a 16K ADMA buffer is

 NOTE, HOWEVER: with either fix, the problem will return after the first
 suspend/resume cycle.  The audio driver has no s/r support at all.  That
 clearly needs fixing, but it's a separate issue.

Ticket URL: <http://dev.laptop.org/ticket/11471#comment:9>
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