750GX cpu freq support

[Kevin Diggs]

Hi,

	 I was hoping that someone might know something about the cpufreq stuff 
and would be willing to take a look at what I have so far.

	It all loads up and tries to run. But if I switch to the conservative 
governor it starts trying to switch to some 4.2 billion KHz (-49000). It 
(the system) seems to eventually freeze up. The ondemand governor sort 
of has the opposite effect. It wants to go to 0 KHz?

	This is built on a module called pll_if that handles the low level 
interface to the PLL register (HID1). It (pll_if) includes an optional 
sysfs attribute that can be used to monkey with the PLL. I have a perl 
script to allow one to modify the PLL in a more human friendly way. Via 
the sysfs attribute, pll_if is useable. So I don't think the problem is 
in it (though it is supposed to prevent you from doing anything stupid, 
like switching to a PLL that is off or modifying the active PLL - but it 
may not be as bullet proof as I would like).

	In particular, the frequency switch in my driver is not synchronous (it 
may not be completed when Target() returns). Don't know if 
cpufreq_core/governors care about this? Is this notifier stuff some kind 
of generic "callback" framework?

	Any investigating tips would be appreciated. I don't know whether 
pll_if is being asked to do something dumb and is doing it or if it is 
freezing up else where.

	"System" is a powermac 8600 with a powerlogix 750GX card in it.

kevin

P.S.:  This will show how much of a novice I am:  What's a "git"?
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