[alsa-devel] [PATCH v5] ASoC: omap-mcbsp: Add PM QoS support for McBSP to prevent glitches

[Tony Lindgren]

* Matt Ranostay <matt at ranostay.consulting> [170109 13:46]:
> On Mon, Jan 9, 2017 at 11:21 AM, Tony Lindgren <tony at atomide.com> wrote:
> > * Peter Ujfalusi <peter.ujfalusi at ti.com> [170109 05:13]:
> >> On 01/05/2017 03:59 AM, Matt Ranostay wrote:
> >> > 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.
> >> >
> >> > Basing the QoS latency calculation on the FIFO size, threshold,
> >> > sample rate, and channels.
> >>
> >> Looks good to me, thank you!
> >>
> >> Acked-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
> >
> > Noticed the following about 10 seconds into playing an mp3 file with
> > mpg123 though:
> >
> 
> Didn't notice that happening for me. But haven't rebased for the last
> couple days.
> Does this happen 100% of the time?

Yeah seems to based on three attempts. This with 4.10.0-rc2-next-20170109.

Tony