Date: Thu, 07 May 2009 00:10:59 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: onemda@gmail.com Cc: mav@freebsd.org, freebsd-current@freebsd.org, freebsd-acpi@freebsd.org, freebsd-mobile@freebsd.org Subject: Re: Fighting for the power. Message-ID: <20090507.001059.-1558772981.imp@bsdimp.com> In-Reply-To: <3a142e750905040240g58152e69p6fcb797a5e026426@mail.gmail.com> References: <49FE1826.4060000@FreeBSD.org> <3a142e750905040240g58152e69p6fcb797a5e026426@mail.gmail.com>
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In message: <3a142e750905040240g58152e69p6fcb797a5e026426@mail.gmail.com>
"Paul B. Mahol" <onemda@gmail.com> writes:
: On 5/4/09, Alexander Motin <mav@freebsd.org> wrote:
: > 2. PCI devices
: > PCI bus provides method to control device power. For example, I have
: > completely no use for my FireWire controller and most of time - EHCI USB
: > controller. Disabling them allows me to save about 3W of power. To
: > disable all unneeded PCI devices you should build kernel without their
: > drivers and add to loader.conf:
: > hw.pci.do_power_nodriver=3
: > To enable devices back all you need to do is just load their drivers as
: > modules.
:
: Unloading modules doesnt put them back into into D3 state.
: You are forced to load some another module again to put wanted device
: into D3 state.
It should. If it isn't, that's a bug.
Warner
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