From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rodney Cacy Subject: Re: understanding acpi Date: Tue, 05 Dec 2006 12:14:04 +0100 Message-ID: <4575547C.6000909@tlen.pl> References: <456EB894.20306@imag.fr> <45741364.5040308@tlen.pl> <45742ECD.6090203@imag.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from d1.imc.pcz.czest.pl ([212.87.226.194]:2153 "HELO d1.imc.pcz.czest.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S967459AbWLELLU (ORCPT ); Tue, 5 Dec 2006 06:11:20 -0500 In-Reply-To: <45742ECD.6090203@imag.fr> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org, Oliver.Henriot@imag.fr You try to break rules and it is not easy so I do not expect that there= =20 is another mailing list where you find an easy answer for your question= =2E In my opinion the acpid is not the right way. It is only for catching=20 acpi events and then run scripts. Using it you can be informed that the= =20 processor changes state from c3->c2 and then you can react for the=20 information by running an application but there is no one which revert=20 the change (it is to force the processor to change state from c2->c3)=20 because the kernel is only the one that can do that. It is a question=20 for me why the battery presence allows the c3 state whilst without it=20 only c2 is possible. I do not know, really. I think that the simplest way to deal with the noise reduction could by= =20 thermal management. Why? I guess the working fan generate the noisy=20 sound :) so let turn it be on less frequently. =46orgot about the "c" states - it is to difficult. For thermal managem= ent=20 is an easy interface in /proc/acpi/thermal_zone. Read about it in the http://www.columbia.edu/~ariel/acpi/acpi_howto.txt, section 8. If it is= =20 too difficult to understand ask about it in other forum (maybe=20 LinuxQuestions.org) and read, read, read... Cheers Oliver Henriot wrote: > Hi, >=20 > Rodney Cacy a =E9crit : >=20 >> I'm not an expert but you can pass a boot kernel option: >> >> processor.max_cstate >=20 > Yes, I'd actually tried setting processor.max_cstate=3D4 a while ago = to=20 > see if this changed anything and indeed, instead of reading > max_cstate : C8 > from /proc/acpi/processor/CPU0/power as I usually get, I got > max_cstate : C4 > Obivious, and no good either, unfortunately. I still ran at C2 on mai= ns=20 > and C3 on battery. > I suspect my settings in /etc/acpi are not good and I'm looking for a= =20 > fine manual I could rtfm in order to understand what I should doo to=20 > fine tune acpi on my machine. Where I'm stuck is to find the fine man= ual=20 > which I'll actually understand (I may not be very smart... ;-) ) and=20 > manage to put into application. >=20 >> More inforamtion in=20 >> http://www.columbia.edu/~ariel/acpi/acpi_howto.txt, section 7. >=20 > Yes, I'm actually trying to understand sections 6.3 through 6.6 of th= at=20 > same document, which I suspect are precisely what I'm looking for and= =20 > also point at /etc/acpi. My relatively limited skills are preventing = me=20 > from getting any further at the moment, but I am confident I will=20 > eventually make something of it. >=20 >> Write me about the results. Now I'm working under suspending sound,l= an=20 >> etc. to save battery but soon I will work with the noise reduction. >> >> Cacy >=20 >=20 > Cheers, >=20 > P.S. considering the level of other discussions on this list, I suspe= ct=20 > I have pointed my questions to the wrong place. Question : is there a= =20 > noob oriented discussion list for acpi? Anyway, sorry for the list=20 > pollution with such "low level" questions. >=20 >> >> >> Oliver Henriot wrote: >> >>> Hi all list subscribers, >>> >>> I'm looking for info on how acpi functions in order to get it to wo= rk=20 >>> the best possible on my computer. It's a Sony laptop (vaio=20 >>> vgn-sz3xp/c, core2duo) running Debian Etch. In particular, I'm=20 >>> looking for ways to reduce thermal dissipation from the CPU as much= =20 >>> as possible, in order to queep the machine as quiet as possible. Fr= om=20 >>> the various docs I've read, so far I seem to understand that C-stat= es=20 >>> is the way to go, throttling being probably not very efficient. >>> >>> When I'm running on batteries, C3 state is active (as shown by cat=20 >>> /prc/acpi/processor/CPU0/power) and is the main state, whereas when= =20 >>> I'm running on mains, C3 disappears and only C1 and C2 remain. >>> >>> My question are : wouldn't it be better if I could use C3 even when= =20 >>> on mains. Wouldn't it be even better with C4? As suggested by "Why = My=20 >>> Cx Power State Is Not Used" I tried unloading various modules (e.g.= =20 >>> those concerning usb but I got stuck with usbcore which refused to=20 >>> unload despite nothing usb being connected) without any success.=20 >>> Being relatively new to GNU/Linux, I'm a bit stuck here and don't=20 >>> know where to look or what to make of this. >>> >>> Any help would be gladly welcome. >>> >>> Cheers, >>> >>> Oliver >>> - >>> To unsubscribe from this list: send the line "unsubscribe linux-acp= i" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>> >> >> >> - >> To unsubscribe from this list: send the line "unsubscribe linux-acpi= " in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >=20 >=20 - To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html