Re: Recent linux-image update broke CPU fan

["Neal P. Murphy" <neal.p.murphy@alum.wpi.edu>]

On Sun, 29 Nov 2015 17:18:51 -0500
"Neal P. Murphy" <neal.p.murphy@alum.wpi.edu> wrote:

> On Sun, 29 Nov 2015 14:35:15 +0100
> Sven Arvidsson <sa@whiz.se> wrote:
> 
> > On Sun, 2015-11-29 at 02:16 -0500, Neal P. Murphy wrote:
> > > I think the last linux-image update broke my CPU fan. OK, it didn't
> > > actually break it. But since the last update, my CPU fan (stock with
> > > vishera 8350 black) will NOT turn faster than about 3500 RPM.
> > > 
> > > I have been using fancontrol for months. It took weeks to get it set
> > > correctly. At maximum speed, I've seen (and heard) the fan turn in
> > > excess of 6500 RPM.
> > > 
> > > Until the recent kernel update, the CPU and case fans have ramped up
> > > with increasing temp and ramped down with decreasing temp. The CPU
> > > never exceeded about 60C when compiling linux using all 8 CPUs for 5
> > > minutes. And that was with a mild overclock (4.4GHz, 1866 RAM at
> > > 2133).
> > > 
> > > Now, the CPU fan will not exceed about 3700 RPM. That's barely fast
> > > enough to keep 4 non-overclocked CPUs cool.
> > > 
> > > Has anyone else experienced this? Is it related to the kernel update?
> > > Or do I have a power supply or motherboard failing (again)?
> > 
> > If this was on a stable system it seems odd, if it was unstable or
> > testing it might just be one of the "charms" of running something that
> > is in development.

It's still odd. But with no change to the OS, the fan speed has returned. So I'm going to conclude that it is related to hardware and/or firmware (flaky NVRAM, flaky power supply, flaky mainboard, &c.), that the kernel update was not the cause.

Thanks,
N