Fan+heat troubles on MacBook Pro

[Steven Noonan]

On Sun, Nov 28, 2010 at 1:36 PM, christoffer.buchholz at gmail.com
<christoffer.buchholz at gmail.com> wrote:
> Hi guys,
>
> I own a MacBook Pro which I bought brand new in January 2010. I have tried
> running Fedora 14 (and 13) on it, but I am having some troubles. Especially,
> the fan is not functioning properly which leads to very hot temperatures
> nearing 70 degrees celcius when I am not doing more than running irssi in a
> terminal.
>
> I having been digging around, and loading the applesmc and coretemp modules
> scored a few degrees. Also running fedora at runlevel 3 didnt do much
> difference, so I guess the problem is not X but the Linux kernel.
> FYI, I am using the nouveau driver and not the proprietary nvidia driver. I
> tried the nvidia driver, but it didnt do any difference, so I went with the
> nouveau one.
> I have tried with powertop and enabling its suggestions, but it didnt help.
>
> I and writing this mail in hope to get some tips back with things I could
> try, and also to see if this is something that is worth filing a bug on, or
> if the issue is somewhere else.
>

Hi Chris,

I had this kind of trouble a couple years ago with a mid 2007 MacBook
Pro, and it ended up being a buggy cpufreq driver which refused to
scale down. I also had similar heating issues when a buggy atheros
driver caused an interrupt storm, which also prevented cpufreq from
doing its job (though it caused more obvious symptoms as well).

Chances are, there's something going on in kernel space that shouldn't
be happening. So you're probably on the right track by checking
PowerTOP. Would be helpful to know a bit more though.

- What kernel are you running?
- What CPU do you have, and what's its rated clock frequency?
- Can you do 'cat
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor' to find out
what cpufreqy scaling governor your machine is using? If it's
'performance', your CPU won't ever scale down to lower frequencies to
save heat/power.
- Can you do 'cat
/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq' a few times
while the machine is idle, and see if it ever scales down?
- What does PowerTOP say? You mention checking it, but didn't say
anything about what it reported.
- It's a long shot, but can you check if anything listed in
/proc/interrupts is getting an inordinate number of interrupts per
second? To find out, you may have to do something like 'cat
/proc/interrupts; sleep 0.5s; cat /proc/interrupts' and see if
anything has changed dramatically.

Steven