[LAU] MusE RtcTimer cannot set freq

Tim E. Real termtech at rogers.com
Sat Nov 3 21:50:29 UTC 2012


On November 2, 2012 01:29:18 PM Pedro Lopez-Cabanillas wrote:
> On Friday 02 November 2012, Clemens Ladisch wrote:
> > Tim E. Real wrote:
> > > I believe there is an RTC/HPET library now.
> > > We should probably try to use it instead of this awkward /sys tree
> > > stuff, eh?
> > 
> > For four years, ALSA's default has been the high-resolution timer, so
> > you don't need to try to use anything.
> 
> This is true when a program (properly) uses the ALSA Sequencer scheduled
> output for MIDI playback, but the last time I've checked MusE it didn't.

Are you saying that we can't have our ALSA timer usage and make it high-res 
 as well? Or we must first jump through a few hoops - ie those settings?
ie the ALSA scheduler does not require you to poke the /sys tree, or wherever?

> This program uses the ALSA timer interface, and immediate MIDI output.

Yes. I noticed that long ago. I'm not knowledgeable enough (or patient?) 
 to implement ALSA scheduling but I did read up on it.
Sometimes it's hard to follow docs of various projects when they 
 don't (can't) show links to kernel header information, or other headers.

But yeah, scheduler definitely much cooler - let ALSA handle all the timing.
Better for high-res, eh?
Question: If we implemented ALSA scheduling instead of 'direct', 
 that would allow us to remove our ALSA timer usage completely, right?

I mentioned one of our devs is trying to get MusE running on BSD.
It has a stripped ALSA support package, also found in other distros, 
 oddly labeled as being specifically for DSSI yet is obviously useful for 
 everyone. Apparently there are no ALSA timers in this package.
So he made the good point that ALSA needs to be a MusE compile option,
 to let Jack handle the particular sound system (OSS).
Slowly getting to that point. I still do remember when I announced our 
 Jack Midi support that someone in LAD urged the very same, I haven't
 forgotten...
Actually our dev asked about removing our ALSA support altogether, 
 but there are benefits to having a native ALSA driver.

Thanks.
Tim.





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