Walking in Light With Christ - hip0's personal blog on System Administration, Free Software, Computer Security and Religion

Thinkpad R61 Linux Power Saving

devoted my whole Sunday on researching how can I lower my laptop power consumption whenworking on battery. A really precious tool that helped me a lot is powertop . Powertop shows which application drains how much from your battery when your laptop moving on battery, it also gives suggestions for various optimizations that stretch the battery usage time. First I took the wrong direction trying to play with powersaved, powernowd. In case you're curious powernowd is good for controling your CPU speed and voltage whether powersaved is a power management daemon. After that I tried to follow some steps on the gentoo's website buit didn't worked, so I remembered that there was something about power saving on the thinkwiki's website. After reading a bunch of pages there and experimenting with acpi. I found out that it's quite easy to set scripts for execution with acpi, all I had to do was put the executed script within the appropriate acpi directory. Two directories were of an interest to me this are the directories /etc/acpi/battery.d and /etc/acpi/ac.d. The 1st one controls the events which happen in case laptop is running on battery the latter one did control what happens in case the laptop is running on AC power.
So as I said after reading suggested optimizations that could be made I ended with 2 little shell scripts which I'm gonna paste below, the 1st one should be putten in /etc/acpi/battery.d, the second one in the ac.d's dir, I personally did choose the name of the two shell cripts be power-save.sh you can name it whatever you like. Be sure to set the executable file on that scripts.
Here are the scripts themselves:

---- CUT HERE ---- /etc/acpi/battery.d
 !/bin/sh
 hal-disable-polling --device /dev/cdrom
 echo 5 > /sys/bus/pci/drivers/iwl3945/0000:03:00.0/power_level
 mount -o remount,noatime /
 echo 1500 > /proc/sys/vm/dirty_writeback_centisecs
 echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
 echo ondemand > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
 xbacklight -set 50
 hal-disable-polling --device /dev/hda
 echo 5 > /proc/sys/vm/laptop_mode
 # enable sound card power saving
 echo 1 > /sys/module/snd_hda_intel/parameters/power_save
 # mute microphone and Line
 ##amixer set Line mute nocap
 amixer set Mic mute nocap
 echo 1 > /sys/devices/system/cpu/sched_mc_power_savings
 for i in /sys/bus/usb/devices/*/power/autosuspend; do echo 1 > $i; done
 # those sysctl's are only available if you have an AHCI compatible SATA 
 # controler and use kernel > 2.6.24-rc2 (or use Kristen ALPM patchset) : 
 echo min_power > /sys/class/scsi_host/host0/link_power_management_policy
 echo min_power > /sys/class/scsi_host/host1/link_power_management_policy
 # turn off the display after 5mn of idling
 xset +dpms
 xset dpms 0 0 300
 # disable tv output
 xrandr --output TV --off # for instance (if "xrandr" above listed a connected output named "TV" that you don't use)
 # disable CRT and DVI output
 echo crt_disable > /proc/acpi/ibm/video
 echo dvi_disable > /proc/acpi/ibm/video
 # disable wake-on-LAN
 ethtool -s eth0 wol d
 # force usage of 100Mbits on LAN card
 ethtool -s eth0 autoneg off speed 100
 # reduce display brightness
 xbacklight -set 50
 umount /mnt/C
 umount /mnt/D
 mount -t ntfs-3g -o noatime /dev/sda2 /mnt/C
 mount -t ntfs-3g -o noatime /dev/sda5 /mnt/D
 #disable uhci-hcd module
 rmmod uhci-hcd
 killall -9 gnome-power-manager
 ----------------------

 ------ CUT HERE ------ /etc/acpi/ac.d/restore.sh
 #!/bin/sh
 xbacklight -set 100
 ethtool -s eth0 autoneg off speed 1000
 mount -o remount,noatime /
 umount /mnt/C
 umount /mnt/D
 mount -t ntfs-3g -o atime /dev/sda2 /mnt/C
 mount -t ntfs-3g -o atime /dev/sda5 /mnt/D
 echo 6 > /sys/bus/pci/drivers/iwl3945/0000:03:00.0/power_level
 hal-disable-polling --enable-polling --device /dev/cdrom
 echo max_performance > /sys/class/scsi_host/host0/link_power_management_policy
 echo max_performance > /sys/class/scsi_host/host1/link_power_management_policy
 echo 0 >/proc/sys/vm/laptop_mode
 amixer set Mic unmute cap
 echo 0 > /sys/module/snd_hda_intel/parameters/power_save
 xset -dpms
 echo 500 > /proc/sys/vm/dirty_writeback_centisecs
 echo 0 > /proc/sys/kernel/nmi_watchdog
 for i in /sys/bus/usb/devices/*/power/autosuspend; do echo 0 > $i; done
 xrandr --output TV --auto
 echo 0 > /sys/devices/system/cpu/sched_mc_power_savings
 modprobe uhci-hcd
 -----------------------

I'm not using the pcmci slot so I black listed it:

 echo pcmci >> /etc/modprobe.d/blacklist
 echo yenta_socket >> /etc/modprobe.d/blacklist
 

In /etc/modprobe.d/ create the file thinkpad_acpi.modprobe and put the following in it:
options thinkpad_acpi hotkey=enable,0xffffff experimental=1 fan_control=1
The above would enable experimental feature which controls the fan so when on battery the fan would turn on and off depending on the thermal indicators of the cpu.
Well that's mostly what I did the battery's estimated time increased to 3.2, 3.5 h before that it was somewhere around 2.5. This means a whole hour more for my Laptop on Linux! Hoora! In order for all this to work you should also read the thinkwiki's page on power saving you need to have custom hdapsd and custom kernel. Now Enjoy your prolonged battery time