[PATCH 0/3] ALSA USB MIDI: Predictable low latency for USB MIDI output

[Takashi Iwai]

On Mon, 16 Mar 2020 11:45:41 +0100,
Andreas Steinmetz wrote:
> 
> On Mon, 2020-03-16 at 09:42 +0100, Takashi Iwai wrote:
> > Thanks for the patches and the analysis.
> > 
> > So, judging from the experiments above, outqueue=1 has no measurable
> > performance regression?  For 4 ports, it's even an improvement.
> > Then we may change the default value.
> > 
> > I guess you kept the old value just to be conservative, but if the
> > number tells a better story and it's no part or ABI, we may consider
> > changing the default for a better performance.
> > 
> > Or, is there any other potential risk by changing this?
> > 
> I'm very careful here. MIDI based equipment (and that includes MIDI
> interfaces) is typically very long lived (I do have equipment that is
> more than 20 years old). Thus I cannot guarantee that changed defaults
> will not harm performance of older equipment.
> 
> I do prefer to keep the current defaults and allow users to, well,
> experiment if modifications to the defaults do work and actually help
> for their hardware. I would not want to break usability of older
> hardware.

OK.  Unless Clemens has any objection, I'm going to take your patches
as-is, then.


thanks,

Takashi