8 March 2006

My Linux on Thinkpad T41p Guide (2)

Posted under: at 20:29

Since first I wrote my Gentoo on IBM Thinkpad T41p guide, there are numerous updates to involved software. Features has been added, bugs has been fixed and new bugs appears. Some parts of the old guide has become irrelevant, outdated and simply wrong.

The following is my attempt to update the guide to reflect the current situation.


I’m now switching to fglrx as it now supports software suspend. Now, 3D acceleration, suspending, and hopefully multi head work at the same time. In /etc/X11/xorg.conf, I added Option "dpms" under “Monitor” section to enable DPMS. I also added Option "UseInternalAGPGART" "on" under “Device” section to use kernel’s Agpgart. For some reason, the Agpgart that comes with fglrx is not as stable as the kernel’s. Added DisplaySize 474 356 under “Monitor” section to keep resolution on 75×75 DPI.

Xv by default is not enabled on fglrx. To enable it, use Option "VideoOverlay" "on" and Option "OpenGLOverlay "off" under section “Device”.

To automatically put the video adapter in power saving mode, I put Option "PowerState" "1" under “Device” section. To get a list of available modes, use aticonfig --list-powerstates. To disable power saving mode on the fly, use aticonfig --set-powerstate=2 --effective=now. Please note that different video card has different power saving power states, be sure to use aticonfig --list-powerstates to see the available power states on your model. My Mobility FireGL T2 has two powerstates, under low voltage mode glxgears runs with a little more than 1000 FPS, and under default state it runs with about 2100 FPS.


CPU Frequency Scaling

With the introduction of ‘conservative’ CPU frequency governor in 2.6.12, it is no longer required to use userspace CPU scaling daemon such as powernowd. Now I just let laptop mode tools change CPU governor to ‘conservative’ when on battery and ‘ondemand’ when on AC power. The cpufreq-conservative and cpufreq-ondemand need to be loaded either statically or loaded as module.

Relevant snippet from /etc/laptop-mode/laptop-mode.conf:

# Should laptop mode tools control the maximum CPU frequency?

# Legal values are "slowest" for the slowest speed that your
# CPU is able to operate at, "fastest" for the fastest speed,
# "medium" for some value in the middle, or any value listed in
# /sys/devices/system/cpu/cpu*/cpufreq/scaling_available_frequencies.


Disabling Disk Syncing

Laptop mode tries to delay write to hard drive but some programs insist on syncing every minute or so. Libnosync solves the problem. Compile it, put libnosync.so in /usr/lib and add /usr/lib/libnosync.so in /etc/ld.so.preload.

Embedded Security Subsystem

This works with tpm_atmel module, it created device /dev/tpm0. However I have no real use for it.


Hard Drive Active Protection System

This one hasn’t matured yet. It works but requires no small amount of tinkering:

The last two steps are probably specific only to early version of this hard drive model (Hitachi HTS726060M9AT00).


26 Responses

Trackback: Use this URI to trackback this entry. Use your web browser's function to copy it to your blog posting.

Comment RSS: You can track conversation in this page by using this page's Comments RSS (XML)

Gravatar: You can have a picture next to each of your comments by getting a Gravatar.

Leave a Comment

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Warning: Comments carrying links to questionable sites will be removed!