From mboxrd@z Thu Jan 1 00:00:00 1970 In-Reply-To: <14404.17703.247016.528826@cpu.wpi.edu> Date: Wed, 1 Dec 1999 12:39:16 +0100 To: Josh Huber , linuxppc-dev@lists.linuxppc.org From: Benjamin Herrenschmidt Subject: Re: wallstreet power usage... Message-Id: <19991201123916.024054@mailhost.mipsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Tue, Nov 30, 1999, Josh Huber wrote: >Hey, for those who know, how could I extend the battery life for my WallStreet >when it's both sleeping, and when it's awake... > >does the /proc/sys/kernel/powersave-nap setting do anything for the wallstreet >series machines? > >With Batmon, it seems that the power usage is like: >powersave-nap current >0 -1350 >1 -1550 > >the number varies, of course...but they appear to be about 200 off from >eachother. > >Doesn't this seem a little backwards to any of you? It seems backwards to what >Paul is doing for the 3400 in the pwrctl script. > >Any other tips? Is it possible to turn off hardware like: ethernet, sound, >video (I know this is a little buggy...for my machine anyway)? > >I ask, because while the machine is sleeping, in about 6 hours 25% of the >battery seems to be used, which is far far more than used when sleeping in >macos. be careful with nap mode, it will turn cache coherency OFF, and so any device doing DMA will end up doing weird things.... Sleeping is another matter. It may still eat power because some devices may not yet be fully powered down. In my latest kernel, I added code to turn off the sound chip, it may help (but you need to have dmasound module insmod'ed or insmod'ed and rmmod'ed at least once for this to work). I'm still wondering about a strange piece of code Apple used in their own sleep stuff, it's possible that without that hack, the PCI bridge doesn't go to sleep. I'll try to do more experiments with that one of those days. Video sleep should work fine as long as you have a correct mclk/pll setting. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/