Saturday, July 11, 2009

LVEE'09

Last week I took part in LVEE'09. LVEE stands for Linux Vacarion/Eastern Europe and it is an international conference of developers and users of free / open source software. Conference format includes reports, workshops, and round tables.

Unfortunately I had no time to prepare my own report, so I was just a listener. Report's thematic was very wide and included:
  • embedded and mobile linux (openmoko, maemo, and some proprietary solutions, for example one from zyxel)
  • IP-telephony solutions (asterisk)
  • using opensource software in different fields, such as: medicine, business, journalism
  • virtualization technologies
After reports in evening there were so-called non-formal discussions, where participants discuss about reports, share their experience, etc. Of course, important part of conference is cooking shish kebab :)

In general, lvee'09 was great!

Here's photo report:
http://picasaweb.google.com/anarsoul/LVEE09#

Lenovo 3000 N100 and ACPI

There was a bug in BIOS of my laptop that annoyed me for long time:

In two words, after resume from hibernate (suspend to disk) fan sticks to the one state. I.e. it's always working (annoying but not dangerous), or it's always stopped (dangerous, can cause overheat) - it's state is not depend on CPU temperature.

Here's some links about it:

http://bugzilla.kernel.org/show_bug.cgi?id=10223

https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/114312


Zhang Rui (thanks to him!) pointed right direction: he provided customized DSDT table with extra debug output in _TMP method. I've tried it, and it showed that one of two thermal sensors shows wrong info after resume. So I wrote new _TMP method that uses only one thermal sensor.

There was one more issue in BIOS - /proc/acpi/battery/BAT1/{info,state} shows hardcoded values, and doesn't perform real query to the smart battery.

I've googled a little bit and found this:
http://hughsient.livejournal.com/5884.html

So, after all I have custom DSDT table that works fine for me :)

Here's patch for DSDT table and here's manual that describes how to apply it.
Also consult http://www.lesswatts.org/projects/acpi/overridingDSDT.php