Thursday, 17 February 2011

Linux Kernel will soon provide better Samsung Laptop support

As posted by Greg Kroah-Hartman on his blog,

Finally, after many years of people asking for this, Linux can now properly support all known Samsung laptop devices. This means we can now handle backlight control, wifi button issues,and the weird "performance mode" keys as well as some of the other function keys.

If you have a Samsung laptop, I suggest looking at the driver in this post on the linux-kernel mailing list, and letting me know if you have any problems with it or not. If your laptop is not listed in the DMI table, please feel free to send me a patch to add it so we can properly support it.

Many thanks to Samsung oh so long ago for providing some of the needed information to get this to work, and to Ingmar Steen for putting all of the pieces together properly to handle the devices that were not being handled by the old in-kernel driver.

http://www.kroah.com/log/linux/samsung_laptop.html posted Wed, 09 Feb 2011 in [/linux]

As a Samsung Laptop user I think this is great news but reading the mailing list and the kernel patch file I saw something interesting.

Some Samsung laptops have different "performance levels"
+ that are can be modified by a function key, and by this
+ sysfs file. These values don't always make a whole lot
+ of sense, but some users like to modify them to keep
+ their fans quiet at all costs. Reading from this file
+ will show the current performance level. Writing to the
+ file can change this value.
+ Valid options:
+ "silent"
+ "normal"
+ "overclock"
+ Note that not all laptops support all of these options.
+ Specifically, not all support the "overclock" option,
+ and it's still unknown if this value even changes
+ anything, other than making the user feel a bit better.

So it seems like there is some confusion as to what the performance levels should do. Well, based on my observations in Windows,

Silent

Set CPU frequency scaling to [Power Saver] + deactivate fan. But if temperature > [Active Fan Trip Point] activate fan on until temp < [Active Fan Trip Point + 10]

Or some other variable

[Active Fan Trip Point] is a BIOS set value which varies according to model/processor. On a Samsung R510 it is set to 71c

Normal 

Set CPU frequency scaling to [Balanced] + Activate BIOS fan control

Overclock
 
Set CPU frequency scaling to [Performance] + Activate BIOS fan control

A more appropriate label for 'Overclock' should be 'Performance'. In fact in Windows this performance level is referred to as 'Performance'

It is important that the Silent mode activates the fan if the [Active Fan Trip Point] has been reached, failing to do so will cause the processor temperature to continue rising until it reaches the critical shutdown temperature.

And not to mention the potential of causing many unhappy Samsung users, claiming Linux killed their laptop.

Sunday, 6 February 2011

How to compile a kernel from kernel.org in Ubuntu 10.04 LTS

This quick how-to is based on http://linuxtweaking.blogspot.com/2010/05/how-to-compile-kernel-on-ubuntu-1004.html

Open a terminal and work through the following set of commands.

Install these packages

sudo apt-get install fakeroot kernel-wedge build-essential makedumpfile kernel-package libncurses5 libncurses5-dev

Run this

sudo apt-get build-dep --no-install-recommends linux-image-$(uname -r)

Create your source directory

mkdir ~/src
cd ~/src

Download and extract your kernel


You can browse for kernels at http://www.kernel.org/pub/linux/kernel/v2.6/ This guide is using kernel 2.6.37.

wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.37.tar.gz
tar xvf linux-2.6.37.tar.gz
cd linux-2.6.37

Configure your Kernel

make menuconfig

Build your Kernel

export CONCURRENCY_LEVEL=3
make-kpkg clean
time fakeroot make-kpkg --initrd kernel-image kernel-headers

General rule, concurrency level = number of processor cores + 1


Install your kernel

cd ~/src

dir        
sudo dpkg -i linux-image-2.6.37_2.6.37-10.00.Custom_amd64.deb
sudo dpkg -i linux-headers-2.6.37_2.6.37-10.00.Custom_amd64.deb

Create the initramfs image

sudo update-initramfs -c -k 2.6.37

Update your grub.cfg

sudo update-grub

Reboot your system


Enjoy your new kernel.

Thursday, 3 February 2011

openSUSE 11.3 with KDE 4.6 (mini review)

Despite the troubles in Novell / Attachmate land, openSUSE remains strong and focused with the availability of KDE 4.6.


Another update to KDE, it's now on version 4.6. Thinking back to the very first KDE 4.x release, there is no doubt that the KDE team have made a lot of progress to this date.

As a desktop environment KDE provides a modern looking and stylish desktop that feels fast and has plenty of eye candy.

Being a KDE fan I decided to give KDE 4.6 a go with openSUSE 11.3 since openSUSE provides the most polished user experience with KDE. By default openSUSE 11.3 ships with KDE 4.4.4 but the team have provided a stable KDE 4.5 repository which I highly recommend.

I believe plans for a stable KDE 4.6 repository are underway but at the moment openSUSE users have the option of using the Factory openSUSE KDE 4.6 repo. Essentially this provides an upstream version of KDE with openSUSE patches which is in the progress of being tested.

So after upgrading openSUSE 11.3 to KDE 4.6, in comparison to KDE 4.5.x there really isnt much difference apart from the odd visual and application tweaks here and there.

Disappointing?

Far from it, under the hood KDE 4.6 has undergone significant changes, such as the removal of HAL and shift to udev, upower and udisks. Improvements to kwin have resulted in a better performance. Overall I am more happy with the lack of obvious changes because I feel it illustrates KDE 4.x is starting to stabilise and mature into a rock solid desktop environment,

End users such as myself are starting to get tired of drastic changes with each update of KDE, the release of 4.6 makes a nice change and hopefully marks a new stage for KDE. A stage that will perhaps focus a bit more on the end user.

So if you are serious about KDE, get openSUSE 11.3.

Smoke some Tumbleweed

If the excitement of KDE 4.6 isn't enough, then why not try the openSUSE Tumbleweed repository?

As announced not so long ago, openSUSE is looking into the possibility of becoming a rolling release.Simply add their Tumbleweed repository to your system to benefit from more up to date and stable packages.Currently this includes kernel 2.6.37.

openSUSE 11.3, KDE 4.6 and Kernel 2.6.37 at more or less at the click of a button!