Date: Mon, 04 May 2009 10:50:19 +0300 From: Alexander Motin <mav@FreeBSD.org> To: Hans Petter Selasky <hselasky@c2i.net> Cc: FreeBSD acpi <freebsd-acpi@freebsd.org>, freebsd-current@freebsd.org, freebsd-mobile@freebsd.org Subject: Re: Fighting for the power. Message-ID: <49FE9E3B.1050509@FreeBSD.org> In-Reply-To: <200905040926.38337.hselasky@c2i.net> References: <49FE1826.4060000@FreeBSD.org> <200905040926.38337.hselasky@c2i.net>
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Hans Petter Selasky 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. > > The new USB stack should turn off USB HC's automatically when not in use. At > least the schedules will get disabled. Did you do any research on this? Sorry, I really was testing it only with previous USB stack. Now I can acknowledge, that new ehci module loading adds only 0.2W for me by default and almost nothing if I power down built-in USB2 web cam connected to it using `usbconfig -u 5 -a 2 power_off`. Great! Thanks! -- Alexander Motin
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