[linux-audio-dev] about MIDI timing...

Chris Cannam chris.cannam at ferventsoftware.com
Wed Oct 25 16:15:47 UTC 2006


Lee:
> This is/was a bug or multiple bugs in the kernel's RTC driver.  It
> started to appear around 2.6.13 because that was the kernel release
> where they regressed the default timer granularity from 1ms to 2.5ms,
> forcing apps like Rosegarden to switch to RTC based timing.

No, it genuinely went from working to broken - it's 
not a case of always being broken but never 
previously being necessary.  It broke first in RT 
kernels, so I'm guessing it broke in mainline with an 
RT patch merge. 

I'm not aware of anyone these days successfully 
using Rosegarden with snd-rtctimer - if anyone out 
there is, do say so.  Either you get a 1000Hz kernel
or you suffer with crap timing. 

Clemens:
> Kernels >= 2.6.15 work.

The most recent such report we had was from a 
user of OpenSUSE 10.1 (with 2.6.16 I think?).  I 
suggested trying an ALSA driver upgrade; apparently it didn't help.  The thread should be easily found in
the Rosegarden list archives by searching for rtc 
and opensuse.

I don't have a computer here to test it on at all 
myself at the moment, I'm afraid.  I will do later.  Honest. 


Chris


More information about the Linux-audio-dev mailing list