Messages in this thread |  | | | Date | Mon, 19 Jan 2004 18:44:23 +0100 | | Subject | Re: Laptops & CPU frequency | | From | Ducrot Bruno <> |
| |
On Wed, Jan 14, 2004 at 04:59:45AM +0000, Dave Jones wrote: > On Sun, Jan 11, 2004 at 12:54:51PM -0500, Robert Love wrote: > > On Sun, 2004-01-11 at 12:44, Matthew Garrett wrote: > > > Is there any realistic way of noticing this sort of change? > > > > Sure. That is how Speedstep works, right? We have an interface for > > Speedstep, so the kernel knows about it. We do not have an interface > > for the proprietary BIOS stuff, I assume, so the kernel is oblivious. > > Speedstep support is one way right now. We tell the CPU "switch to this mode" > and it does. What we don't know how to do in cpufreq is detect when someone pulls > the power out, or plugs back in. BIOS SMM magick happens, and it all > gets taken care of transparently without us having a clue that anything > happened. > > We *could* hook into the APM 'power source changed' notifiers, (and I > guess ACPI has something similar somewhere). That should take care of things. > > > But if you had the docs, I suppose you could code a solution and tie it > > into the cpufreq code, just as we have proper support for Speedstep, > > Longrun, etc. > > Of all the implementations I've played with (longhaul/powernow/speedstep-smi) > speedstep is the only one that does funky shit with SMM. The others are quite > dumb (and friendly) in comparison. (Ie, nothing happens on power source change)
I'm wondering if there is a need to get bios ownership like in the speedstep-smi if not in acpi mode, in speedstep-ich?
Anyway speedstep-ich should be fine if you explicitely configure BIOS in order to boot always in high performance mode.
-- Ducrot Bruno
-- Which is worse: ignorance or apathy? -- Don't know. Don't care. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |