PowerMac PMU programming
benh at kernel.crashing.org
Mon Jun 11 09:03:13 EST 2012
On Sun, 2012-06-10 at 09:29 -0400, Justin Hibbits wrote:
> I'm working on various PMU bits for FreeBSD (I know, not related to
> Linux), but running into some problems, which the Linux crowd may be
> able to help with, as it's already solved for Linux. I've managed to
> get it to sleep for performing the sleep operation and for the CPU speed
> switch on MPC7455-based machines, but it goes catatonic, not waking
> up. I've installed the reset vector pointer at 0x0080, which both OS X
> and Linux do, and flush the caches, but no luck. During development of
> the Linux driver was this ever encountered? Any assistance would be
> greatly appreciated, I've been banging my head against this off and on
> for about 8 months now.
> Thanks for any assistance. I'm not subscribed to the list, so please
> keep my address in replies.
Yes it was :-) pretty much any bug even minor during that process will
cause just that :-)
One thing paulus did that helped us a lot initially was write a little
synchronous version of the PMU send command and use it to blink the PMU
LED very early on when resuming from sleep, which allows us to debug a
It takes quite a bit of work (see the code in radeonfb) to get the
graphics back, so most of the time you come back with nothing on screen.
If your machine is not a laptop, there are other possible
considerations, such as the need to restore the PCI-PCI bridge that
might be above the macio chip very early on, before you try to restore
macio itself (we don't do that in Linux at this stage).
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