Samsung N120

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Revision as of 19:30, 30 December 2009 by Pwd (talk | contribs) (add ln to Intel Graphics)
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This article aims on providing the informations on installing and setting up Arch Linux on the Samsung N120. Basically I used information from Samsung NC10 netbook wiki.

A lot of the information is derived from the NC10 Arch Forum and N120 Arch Forum and several hints scattered around in the ArchWiki.

Prior to Installation, Common Issues You Should Be Aware Of

  • Installation from USB flash works after you add acpi=off to the kernel parameters.
  • On kernel 2.6.30 webcam is working but not for Skype, but with kernel 2.6.31 from testing repository it works (with LD_PRELOAD trick, i.e. start skype in the following way: $LD_PRELOAD=/usr/lib/libv4l/ /usr/bin/skype or write your own bash script)
  • Suspend to RAM and Suspend to Disk works perfectly on 2.6.30 and 2.6.31
  • AFAIK, there is no known good way to map Fn+(up/down) for controlling brightness. Everything else can be mapped through xbindkeys or using trick from ubuntu wiki (below).


You can use the usb image provided at the official download locations or the iso, if you have an external optical drive. If installation fails try to add acpi=off to the kernel parameters.

Configure your installation


Should work out-of-the-box now. WLAN uses the ath5k module and LAN, sky2.


Initial Brightness

The full brightness can be set with the following command

setpci -s 00:02.1 F4.B=FF

where FF is the highest level of brightness. That parameter moves in the range 00..FF. Don't set it too low because your backlight will turn off! I tried different parameters and optimal are F.4B=45 or F.4B=50. I added setpci -s 00:02.1 F4.B=40 to my /etc/rc.local.

Graphics Adapter

The Video controller is a typical Intel Graphics chipset that works with the xf86-video-intel driver (or xf86-video-intel-new from AUR)

To save some interrupts and therefore power you can disable dri in your xorg.conf. This disables 3D effects but if you don't need them this could be an option.

Section "Device"
Option "NoDRI"
Identifier "Card0"
Driver "intel"
VendorName "Intel Corporation"
BoardName "Mobile 945GME Express Integrated Graphics Controller"
BusID "PCI:0:2:0"

External VGA

External VGA works out of the box with xrandr

in order to prevent problems when switching to console or when unplugging the external monitor, make sure to specify the frequency along with the mode, for example :

xrandr --output VGA --mode 1280x1024 --rate 60

You can also use randr frontend, lxrandr for example.

Dual head positioning works also perfectly : Xorg#Multi-monitor_setups


The audio device is an Intel HD. Since alsa 1.0.19 distributed in archlinux extra repository, you don't need to manually install alsa driver. Everything is working out of the box: onboard microphone and speakers, audio off on earphone plugging.

Troubleshooting :

  • If the volume is too low, or lower than in Windows run alsamixer, and set "front" to 100%.
  • If the microphone does not work, press F4 in alsamixer and play with the settings (boost to 0, digital and capture to mid-values, and input to front-mic should be a sane default).

Note that settings can be saved with "alsactl store"

  • One user reported that he had to disable every snd module in his rc.conf except for two: snd_hda_intel and snd_pcm_oss.
  • [deprecated] if the speakers don't mute when you plug in headphones, you may need to compile alsa.

Download latest alsa build. Extract the tar.bz2 and open a console on alsa source folder

1.execute this command : ./configure --with-cards=hda-intel --with-oss=yes --with-sequencer=yes
2.execute this command : make
3.execute this command : sudo make install
4.get alsa-utils with pacman
5.configure sound volume with alsamixer , reboot , and enjoy :)

Suspend and Hibernate

Pm-suspend should work correctly without any quirks at the moment.

You can use this command not only to suspend from terminal but also in combination with acpid

If after closing the lid your machine doesn't wake up from suspend correctly and needs to be resumed multiple times, you can try using the following workaround. This is an excerpt from /etc/acpid/ file:

       if [ `/bin/awk '{print $2}' /proc/acpi/button/lid/LID0/state` = closed ]; then

In contrast hibernate works without "modifications" (except the ones mentioned in the pm-utils article).

If you are a kde4/kdemod user you can take advantage of powerdevil (included in kdemod-core/kdemod-kdebase-workspace since release 4.2). Screen brightness, cpu scaling, suspend and hibernate all work flawlessly, without any hack.

Right after resume you may notice (i.e. in powertop) lost support for C2 and C4 CPU states. Don't panic. Those modes are likely to return in several minutes.

Fn Keys

You need at least kernel to get the Fn keys to work correctly.

(Volume Controls worked out of the box in kdemod 4.2)

To bind the Fn keys to action, read Extra_Keyboard_Keys#The_quick_way and also Extra Keyboard Keys in Xorg. The suspend key (Fn+ESC) and disable touchpad (Fn+F10) keys should work out of the box. Note, that suspend key is handled in /etc/acpi/ (see "power/sleep" case entry). If you use pm-utils, you should substitute the default action with the call to pm-suspend or pm-hibernate.

This tweak taken from Ubuntu wiki. To get volume and brightness Fn keys work in Gnome you have to make sure that gnome-power-manager is running and add ";N120" to the list of Samsung models in /usr/share/hal/fdi/information/10freedesktop/30-keymap-misc.fdi, i.e.

<match key="/org/freedesktop/Hal/devices/computer:system.hardware.product" 


<match key="/org/freedesktop/Hal/devices/computer:system.hardware.product" 

Also you can play with xbindkey. As an example, here is how to bind the keys for volume control :

1) install xbindkeys (and xbacklight from package xorg-server-utils for brightness control):

pacman -S xbindkeys xorg-server-utils

2) crate a config file in your home directory :

vi .xbindkeysrc

3) with the following content :

"amixer sset Master 2+ &"
    m:0x0 + c:176
"amixer sset Master 2- &"
    m:0x0 + c:174
#"amixer sset Master 0 &"
"amixer sset Master toggle &"
    m:0x0 + c:160
#"sudo pm-suspend"
#    m:0x0 + c:223
"xbacklight +10"
    m:0x0 + c:233
"xbacklight -10"
    m:0x0 + c:232

For your NC10 Fn keysums may differ. If any Fn keys don't work with the above .xbindkeysrc, you should check the keysum values with

xbindkeys -k

4) run xbindkeys :


and volume control should work within an X session !

to add aditional bindings, you can get the codes of most of the Fn-keys with

xbindkeys -k

For the keys that are not recongnized, see

dmesg |tail

to make the kernel recognize them.

(If your Screen is not bright enough, boot into Windows and set the Brightness to maximum)

(you can adjust Brightness during the boot process without returning into Windows and you need to set maximum brightness on battery only mode)

Alternatively, you can add needed broghtness level on the boot, simply add line setpci -s 00:02.1 F4.B=FF (00..FF) to your /etc/rc.local.

Saving Power

Make sure to read Laptop#Suggestions_for_saving_power

Here is a suggestion of things to add to /etc/rc.local to save some power, most of which are suggestions from "powertop".

# /etc/rc.n120: various init and power saving stuff for samsung n120.
# avoid too many power up/down of hard drive, taken over by laptop-mode-tools anyway
hdparm -B 255 /dev/sda

#disable bluetooth 
#(alternatively you can disable bluetooth in rc.conf: MODULES=(... !btusb ...))
hciconfig hci0 down ; rmmod btusb

# enables on-demand cpu freq scaling (requires cpufreq modules) :
echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo ondemand > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor

### turn off wifi
#       ifconfig wmaster0 down
#       echo "wifi is shut down"
# You can also disable wifi module in /etc/rc.conf: MODULES=(.. !ath5k ...)
# or 
rmmod ath5k
#The pdflush writeback daemons will periodically wake up and 
#write "old" data out to disk. This tunable expresses 
#the interval between those wakeups, in 100'ths of a second.
#Setting this to zero disables periodic writeback altogether.
echo "1500"| tee -a /proc/sys/vm/dirty_writeback_centisecs

#dirty_ratio contains, as a percentage of total system memory, 
#the number of pages at which a process which is generating 
#disk writes will itself start writing out dirty data.
#echo "20"| tee -a /proc/sys/vm/dirty_ratio

#dirty_background_ratio Contains, as a percentage of total system memory, 
#the number of pages at which the pdflush background 
#writeback daemon will start writing out dirty data.
#echo "10"| tee -a /proc/sys/vm/dirty_background_ratio

#Not sure
#echo "1"| tee -a /sys/devices/system/cpu/sched_smt_power_savings

#The value of the laptop_mode knob determines the time between the 
#occurrence of disk I/O and when the flush is triggered. 
#A sensible value for the knob is 5 seconds. 
#Setting the knob to 0 disables laptop mode.
echo "5" | tee -a /proc/sys/vm/laptop_mode

# CPU undervolting
echo "12:24 10:20 8:15 6:15"| tee -a /sys/devices/system/cpu/cpu0/cpufreq/phc_controls
echo "12:24 10:20 8:15 6:15"| tee -a /sys/devices/system/cpu/cpu1/cpufreq/phc_controls

# autosuspend webcamera  ****does this really work ????****
echo "auto" | tee -a /sys/bus/usb/devices/1-8/power/level
echo "1" | tee -a /sys/bus/usb/devices/1-8/power/autosuspend

## sound chip power save mode
## => disabled because it makes some high frenquency noise...
#echo "10" | tee -a /sys/module/snd_hda_intel/parameters/power_save

#Set initial brightness level
#setpci -s 00:02.1 F4.B=50
setpci -s 00:02.1 F4.B=35

Use laptop-mode-tools

pacman -S laptop-mode-tools

and configure it to suit your needs in /etc/laptop-mode/laptop-mode.conf Here again some suggestions :

#turn off hard-drive after 10min on AC and 2min on battery (prevents freezes when accessing hd often)


# prevents too many parking of heads while still saving some power on battery.