[LAU] Ardour 2.1 Mixer Levelmeters acting very slow with acpi=off

[Edgar Aichinger]

I can fully confirm now what Susanne described, on a desktop machine (32bit 
AthlonXP 2000+). I guess the freeze I was describing in my previous posting 
was unrelated, I could boot with acpi=off this time without problem.

With acpi=off, I get significantly less xruns at a given frames setting.
Clock source is tsc, and i don't see the "Clocksource tsc unstable 
(delta = xxx ns)" message at boot. Every meter in ardour (2.0-ongoing,
checkout from yesterday, the new track header meters exhibit the same 
behaviour) shows extremely slow falloff, no matter what the corresponding 
option is set to.

Am Montag, 19. November 2007 schrieb Susanne Schneider:
> Thomas,
> I do not get anything like:
> 
> "Clocksource tsc unstable (delta = -107437170 ns)"
> in dmesg...
> 
> when booting with "acpi=off",
> cat /sys/devises/..../current_clocksource  returns: "tsc"
> 
> when booting in regular mode (acpi enabled),
> cat /sys/devises/..../current_clocksource  returns: "acpi_pm"
> 
> thanks and best regards
> Susanne 
> 
> 
> Thomas Kuther schrieb:
> > On Mo, 19.11.07 10:46 susemuse27 at gmx.de wrote:
> >
> >   
> >> hi,
> >> I should have known this earlier: when starting my 2.6.24.rc2-rt1
> >> with option "acpi=off" the audio performance increases significantly
> >> and I could be happy - but - the levelmeters in Ardour's Mixer are
> >> now acting strangely: They rise quickly but the falloff rate is at
> >> lowest level and can't be adjusted. I've tried with a different
> >> kernel, 2.6.23.1-rt11 - it's the same. Of course I can live with
> >> that, it doesn't prevent me from enjoying my musical activity, but it
> >> takes some patience... With acpi on action Ardour works fine. Did
> >> anybody make similar experience and can give me a hint where to start
> >> my  investigations? thanks Susanne
> >>
> >> data:
> >> Asus Laptop AMD Athlon 64
> >> ATI-MobilityRadeon9700
> >> openSuse 10.2-32Bit
> >> USB-Lexicon Omega Studio
> >> Ardour built with VST-support
> >>
> >>     
> >
> > Hi Susanne,
> >
> > this sounds like a problem with the clocksource.
> > That could be caused by powernow-k8 and cpufrequency scaling.
> >
> > I assume when the cpu is powered down right after startup, you see some
> > messages in dmesg saying:
> > ------
> > Clocksource tsc unstable (delta = -107437170 ns)
> > ------ 
> >
> > If so, you could try to disable cpu frequency scaling
> > or make sure the system starts and runs with performance governor.
> >
> > cat /sys/devices/system/clocksource/clocksource0/current_clocksource
> > shows the currently used clocksource. Please post the output of that
> > when booting with acpi=off and acpi enabled.
> >
> >
> >   
> > ------------------------------------------------------------------------
> >
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> >   
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