Intel Ivy Bridge processor with HD Graphics 4000 vs. kernel 3.2

One thing I didn’t know when I swapped Ubuntu for Linux Mint is that Linux Mint marks software packages by how safe they are on a scale of 1 to 5. By default, only packages level 1 to 3 are installed. Kernel upgrades are marked as dangerous packages (level 5 — ones that might break the system), so they won’t be installed or shown. To install/show them, one has to change the preferences in Update Manager. (Or do a manual upgrade via sudo apt-get dist-upgrade).

Apparently, Intel Ivy Bridge processors that comes with HD Graphics 4000 GPU are a known problem for Linux kernel 3.2 series, which is used by Ubuntu 12.04 and Linux Mint 13 (both LTS). My Samsung Series 9 laptop, which uses a Intel Core i5-3317U processor), is currently affected by this bug https://bugs.launchpad.net/ubuntu/+source/linux/+bug/999910 (also http://forum.linuxmint.com/viewtopic.php?f=47&t=112543). It seems the proposed solution is to either move to kernel 3.4 or upgrade to Ubuntu 12.10 or Linux Mint 13, as they use kernel 3.5.

To change the kernel version, the instructions are here: https://wiki.ubuntu.com/Kernel/MainlineBuilds. I certainly hope that fixes for this bug will make it to kernel 3.2 as well.

p/s: a quick way to get system information: inxi -F
p/p/s: a useful tool to install for laptops: sudo apt-get install laptop-mode-tools. Once installed, it can be configured via /etc/laptop-mode/laptop-mode.conf.

Wireless problem in Ubuntu 10.04

If your laptop is using an Intel wireless card when running Ubuntu 10.04, your connection might degrade over time. The bug description can be found here. It seems to affect 5100, 5300, 6100, 6300 series Intel cards. The implemented workaround is to temporarily disable the 802.11n mode. This is done by the file /etc/modprobe.d/intel-5300-iwlagn-disable11n.conf which contains a line:

options iwlagn 11n_disable50=1

It seems like after about 2 years, the permanent fix hasn’t arrived. If you are unhappy with this workaround, you can change the switch from 1 to 0. Then do:

sudo modprobe -r iwlagn
sudo modprobe iwlagn

You can check the wireless performance by comparing outputs from iwconfig before and after the change. If the Bit Rate increases, you can keep the setting; otherwise, you can change it back. Thanks to http://ubuntuforums.org/showthread.php?t=1592846

Dual monitor in Ubuntu 8.04 for Intel Graphics

It really couldn’t be simpler to plug in a second monitor to your laptop and increase your screen real estate in Ubuntu 8.04. The instructions that follow is for integrated graphic card (in my case, it’s Intel 810 graphics driver for laptop). First, use xrandr in terminal to see how many displays are connected/detected by Ubuntu (usually LVDS refers to your laptop screen, and VGA is your external monitor). Once all your displays are connected, enable dual monitor support by doing:

xrandr --output LVDS --mode 1024x768 --pos 0x0 --output VGA --mode 1280x1024 --pos 1024x0

The arguments mode and pos after output LVDS (or VGA) define the screen resolution and which part is displayed in that screen, respectively. For instance, when you used the above command, the graphics controller created a virtual screen that is 2560×1024 large. The block of 1024×768 starting from the top-left corner (0x0) will be displayed in LVDS, while the block of 1280×1024, starting from 1024×0 will be displayed in VGA. There is a missing block of 1024x(1024-768) starting from 0x768 that is not displayed at all, but I can live with that.

The first time you use the above command, you might get an error complaining “xrandr: screen cannot be larger than 1024×800 (desired size 2560×1024)”. In that case, you need to edit /etc/X11/xorg.conf (remember to create a backup). Insert these lines in between Section "Screen" and its corresponding EndSection

SubSection "Display"
Virtual 2560 1024
EndSubSection

The two numbers assign the (maximum) size of your virtual screen.