#1420 BLOC Trial-2: Audio driver for AD1888 - power verification.

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#1420: Audio driver for AD1888 - power verification.
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  Reporter:  jg           |       Owner:  cjb    
      Type:  enhancement  |      Status:  new    
  Priority:  blocker      |   Milestone:  Trial-2
 Component:  kernel       |     Version:         
Resolution:               |    Keywords:  power  
  Verified:  0            |  
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Old description:

> The Analog Devices AD1888 can disable all sections of itself it is not
> using.  As it can drive 5.1 audio output, for example, it is important
> that we verify that all but the stereo channels are disabled.
>
> It also has a "deep sleep" feature, in which it can be entirely disabled.
> If its device driver is closed, the AD1888 should be put into deep sleep,
> and restored when the device opened.

New description:

 The Analog Devices AD1888 can disable all sections of itself it is not
 using.  As it can drive 5.1 audio output, for example, it is important
 that we verify that all but the stereo channels are disabled.

 It also has a "deep sleep" feature, in which it can be entirely disabled.
 If its device driver is closed, the AD1888 should be put into deep sleep,
 and restored when the device opened.

 .. but, currently the mic LED is not turning off when the device is idle.
 This bug investigates that first.

Comment (by cjb):

 Hi Jaya,

 Let's move the "driver doesn't power down when idle" bug over here, and
 leave #1735 for the popping problem.

 I took a (large, attached) systemtap log of all snd_* function entry (so,
 it includes snd_{ac97,cs5535audio,pcm}* and more), in case it helps us
 figure out which functions are failing to fire.  I can write a more
 complex script to do anything systemtap can do (e.g. print function
 arguments) if you can think of what else would help.

 Thanks!

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Ticket URL: <http://dev.laptop.org/ticket/1420#comment:10>
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