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

[Andreas Steinmetz]

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.

Regards
-- 
Andreas Steinmetz