Date: Fri, 8 May 2009 10:34:52 +0000 From: "Paul B. Mahol" <onemda@gmail.com> To: "M. Warner Losh" <imp@bsdimp.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: <3a142e750905080334qb62dcb5hcd07ce028a4ff035@mail.gmail.com> In-Reply-To: <20090507.001059.-1558772981.imp@bsdimp.com> References: <49FE1826.4060000@FreeBSD.org> <3a142e750905040240g58152e69p6fcb797a5e026426@mail.gmail.com> <20090507.001059.-1558772981.imp@bsdimp.com>
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On 5/7/09, M. Warner Losh <imp@bsdimp.com> wrote: > 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. It's a bug. On machine resume(pci_resume), pci_cfg_restore() is called causing D3 -> D0 for all devices(including not attached ones). Unloading module/detaching device doesn't call pci_cfg_save. Should device_detach routine be used or new one like pci_driver_removed() implemented? -- Paul
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