Re: [PATCH review for 4.9 39/50] ASoC: omap-mcbsp: Add PM QoS support for McBSP to prevent glitches

[Levin, Alexander (Sasha Levin)]

On Mon, Oct 09, 2017 at 09:36:56AM +0100, Mark Brown wrote:
>On Sat, Oct 07, 2017 at 10:36:55PM +0000, Levin, Alexander (Sasha Levin) wrote:
>> From: Matt Ranostay <matt@xxxxxxxxxxxxxxxxxxx>
>>
>> [ Upstream commit 9834ffd1ecc3a401d0ce64c2d4235a726da6d4f9 ]
>>
>> We can get audio errors if hitting deeper idle states on omaps:
>>
>> [alsa.c:230] error: Fatal problem with alsa output, error -5.
>> [audio.c:614] error: Error in writing audio (Input/output error?)!
>>
>> This seems to happen with off mode idle enabled as power for the
>> whole SoC may get cut off between filling the McBSP fifo using DMA.
>> While active DMA blocks deeper idle states in hardware, McBSP
>> activity does not seem to do so.
>
>This seems rather invasive and fancy for stable material - people might
>want it in production but they may also not have enough power management
>enabled to be seeing the problems it fixes.

Fair enough, dropped.

This patch has been around for a while now, and had no fixes which is
why I preferred to originally take it anyway.

-- 

Thanks,
Sasha