Date: Tue, 30 Jul 2002 12:00:01 +0200 From: Gary Jennejohn <garyj@jennejohn.org> To: Michael Nottebrock <michaelnottebrock@gmx.net> Cc: freebsd-current@freebsd.org Subject: Re: AMD low power hacks Message-ID: <200207301000.g6UA01Lt007779@peedub.jennejohn.org> In-Reply-To: Your message of "Mon, 29 Jul 2002 21:03:48 %2B0200." <3D459194.70206@gmx.net>
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Michael Nottebrock writes: > The following is an OpenPGP/MIME signed message > created by Enigmail/Mozilla, following RFC 2440 and RFC 2015 > --------------enig8A086DA17DCB77CC40984CC4 > Content-Type: text/plain; charset=us-ascii; format=flowed > Content-Transfer-Encoding: 7bit > > I've been wondering lately why my AthlonTB runs at a quite high > idle-temperature and I came across this page: > > http://vcool.occludo.net/VC_Theory.html > > Does someone feel like getting something similar into our kernel? > If you have a VIA KT266A chipset then you can do something like this: # turn on HALT bit in register 0x95 of the KT266a -> CPU runs much cooler # NOTE: the register had 0x1c when I checked it echo Enable halt bit in KT266A /usr/sbin/pciconf -w -b pci0:0:0 0x95 0x1e which I have in /etc/rc.local. My Athlon runs about 15 C cooler with this. Bit 1 of register 0x95 controls idling of the CPU. Here's a step-by-step description: Do the following as root: 1) pciconf -l -v this lists all the PCI chipsets found at boot time. I see agp0@pci0:0:0: class=0x060000 card=0x30991106 chip=0x30991106 rev=0x00 hdr=0x00 vendor = 'VIA Technologies Inc' device = 'VT8366/A Apollo KT266/A,KT333 CPU to PCI Bridge' class = bridge subclass = HOST-PCI So I have a KT266(A) at pci0:0:0 2) pciconf -r -b pci0:0:0 0x95 0x1c Bit 1 isn't set 3) pciconf -w -b pci0:0:0 0x95 0x1e turns on bit 1. --- Gary Jennejohn / garyj@jennejohn.org gj@freebsd.org gj@denx.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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