Re: #12596 LOW 13.1.0: XO-4 sound streams hang over suspend/resume (was: [CL4] Movie Player can’t be closed.)

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#12596: XO-4 sound streams hang over suspend/resume
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           Reporter:  tomyin        |       Owner:  dsd          
               Type:  defect        |      Status:  new          
           Priority:  low           |   Milestone:  13.1.0       
          Component:  not assigned  |     Version:  not specified
         Resolution:                |    Keywords:               
        Next_action:  never set     |    Verified:  0            
Deployment_affected:                |   Blockedby:               
           Blocking:                |  
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Comment(by dsd):

 I can't quite figure this one out.

 Firstly, the mmp-pcm offers flag  SNDRV_PCM_INFO_RESUME which suggests
 that it has complete suspend/resume handling. It doesn't - the
 suspend/resume code is commented out.

 Trying to enable the suspend/resume code: doesn't work. I suspect it is
 let down by the lack of suspend/resume routines in tdma. Attached as snd-
 debug.patch here.

 By dropping SNDRV_PCM_INFO_RESUME the stream will simply be fully stopped
 and restarted during suspend and resume, should be foolproof, and thats
 what we do on XO-1.75. However that doesn't work either. No tdma
 interrupts arrive when the stream is restarted during resume. I went to
 some extra steps to make sure that the right info is reprogrammed during
 resume, and I checked TDMA register dumps from just before enabling the
 DMA channel, no difference between the failing and working case. Attached
 as tdma-sr.patch here.

 Next step would be to check the ICU registers, make sure the interrupt is
 really unmasked, and look for other reasons why DMA interrupts would not
 be happening.

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Ticket URL: <http://dev.laptop.org/ticket/12596#comment:3>
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