Re: Fan speed and Heat
On Nov Sun 09 2003 22:15, Benjamin Herrenschmidt wrote:
>
> >
> > My previous laptop, an old Pentium 233MMX Toshiba, used to have an
> > address that when written some values, it would start/stop the internal
> > fan. I don't know if something similar exists for the Powerbook, but
> > sometimes, the fan kicks in when the computer is iddle doing nothing (I
> > mean, it kicks in when it receives mail, but I hardly believe it can
> > take soooo much power as to launch the fans!) and it would be nice to be
> > able to do something about it.
> >
> > How good is the power control in the Powerbooks? any ideas/suggestions?
>
> Each single apple motherboard uses a different fan control mecanism
> and none of them is documented and none of them is opensourced in
> darwin... On some machines, the thermostat is configured once for
> all by the firmware and seem pretty happy that way, on others, it
> seems the firmware setting is a bit too "paranoid" and would benefit
> from some work, and finally, some machines seem to lose the firmware
> setting during sleep. But so far, we just lack informations about
> how those things work on most models. The albooks seem to use known
> industry thermostat though, it may be possible to write drivers for
> them, though I don't have time to dive into that now. Every single
> motherboard model made by apple need a specific driver for that it
> seems :(
Mmmmm.... that is a pity :( At least, I know that you know about it :)
Meaning that, perhaps, some day, Apple will consider the "old"
Powerbooks "obsolete", and thus the software/firmware that they use in
them "legacy", and maaaaaybe, they would release it under
GPL/BSD/whatever.
I seriously think that Apple/Many other companies should realise that
their profit is made in the first year of owning a piece of hardware,
and that they would make consumers very happy if they make available
info and source to improve the use of their machines. Specially when
many people has enough knowledge to devote a couple of weeks writing
something so useful. Hey! Even better! If they see smart ideas when
someone improves their stuff, they could do it much better! :)
Well, if I ever talk to some people at Apple, I will try to raise the
issue :) Who knows? Perhaps they will listen! :)
And, out of topic a little bit...
How do you write all that low-level stuff?? :) I am not a "low-level
guy", but I am usually interested in this kind of things... do you run a
kernel inside a linux system and debug it? You just read the doc on a
specific piece of hardware, write a kernel module, and launch a kernel
inside Linux through a debugger to see how it "talks" to the hardware? I
bet this must be bloody hard when working with graphic cards! Heh, you
can blank the whole thing and not be able to see anything!! :)
BTW, how do you produce the magic keys in Mac (once you activate them in
the kernel)? I tried to google it out, but didn't manage to search for
the right thing :)
Thanks again for all the work you do in the ppc kernel, Ben!
--
J. Javier Maestro
<jjmaestro@computer.org>
http://rigel.homelinux.com
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