Re: Sporadic envstat(8)

[Sad Clouds <cryintothebluesky%googlemail.com@localhost>]

On Thu, 2 Dec 2010 07:39:44 -0500
Michael <macallan%netbsd.org@localhost> wrote:

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> Hello,
> 
> On Dec 2, 2010, at 5:47 AM, Sad Clouds wrote:
> 
> > Hi, on my nettop with Intel Atom D510 CPU, envstat() seems to behave  
> > a bit sporadically. If I boot the machine from cold and run  
> > envstat() it reports no drivers registered. However if I let the  
> > machine run for a few minutes and reboot it, then envstat() reports  
> > CPU temperature.
> >
> > Anyone knows why NetBSD envsys does not pick up temperature sensors  
> > when booting from cold?
> 
> Which driver is it? One possibility would be that the sensor takes a  
> while to (literally) warm up and provide valid output which an over  
> eager driver might interpret as malfunction and therefore doesn't  
> attach.
> I've seen this with the built-in thermal sensor in PowerPC G3 CPUs -  
> up to a few minutes after power up it reads temperatures barely above  
> freezing.

Which driver? I don't know, it doesn't say much. When sensors are working, 
running 'envstat -D' gives the following:

coretemp0 (checking events every 30 seconds)
coretemp1 (checking events every 30 seconds)
coretemp2 (checking events every 30 seconds)
coretemp3 (checking events every 30 seconds)

Your point about sensor taking a while to warm up is what I was thinking, 
however if that's the case, envsys framework should be intelligent enough to 
figure this out.

My other thought was maybe the hardware was hiding the sensors, until the 
temperature was high enough that they were usable. Maybe envsys framework 
cannot cope with such dynamic actions? Who knows...