[pulseaudio-discuss] avoid increase watermark for low latency capture

[pl bossart]

> When meet Overrun or Underrun, PA will increase watermark. Due to some
> hardware limitation, the hw_ptr will not be updated in PA's request latency.
> So there maybe some cases "faked overrun/underrun". Take capture for
> example, when Pulseaudio was waken up to read new capture data from driver,
> and find the "available" area is much more than the record space. Although
> it's fast enough to read out all data in short time, PA regard that as
> "overrun" and increase watermark/latency step by step, that's really
> useless.
> So attached patch used to avoid such case and only increase
> watermark/latency in real "overrun" case.

Humm, it's not clear what problem you are trying to solve and on what
platform. Looks like a very old MRST firmware/driver?
If your driver doesn't update the hw_ptr, then how can you know if
this is a real or a fake overrun?
-Pierre