Samsung N148 PLUS, no brightness control

[bicol_willem]

Hi guys 'n doll's, any one knows a workaround this problem?
I installed PCLinuxOS on this netbook of a lady friend and it works very fine, as expected.
Just one little glitch..... we can't control brightness of the screen. We see the progress bar moving up and down, when trying, but the screen itself is always at one and the same brightness. We could do with some more brightness.
Desktop is KDE fully updated. Kernel is 2.6.38.8-pclos3.bfs
Anyone?

[Ɗα√ϵς§]

I'm afraid that I had the same problem on an N150 which I installed for someone - that is using LXDE with gnome-power-manager so the problem seems to be elsewhere - maybe a kernel update will fix it at some point ?

[AS]

Hi guys 'n doll's, any one knows a workaround this problem?
I installed PCLinuxOS on this netbook of a lady friend and it works very fine, as expected.
Just one little glitch..... we can't control brightness of the screen. We see the progress bar moving up and down, when trying, but the screen itself is always at one and the same brightness. We could do with some more brightness.
Desktop is KDE fully updated. Kernel is 2.6.38.8-pclos3.bfs
Anyone?

I can provide only some hints: the problem exist because of samsung not using the standard ACPI commands to control the brightness, however there exist a kernel module that should take care of the difference: samsung-laptop.

as of kernel 2.6.38.8 the following are the supported models:

# modinfo samsung-laptop
filename:       /lib/modules/2.6.38.8-pclos3.pae/kernel/drivers/platform/x86/samsung-laptop.ko.gz
license:        GPL
description:    Samsung Backlight driver
author:         Greg Kroah-Hartman <gregkh@suse.de>
srcversion:     882473D8EE6A77A25E825C2
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*P460*:rn*P460*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*R70/R71*:rn*R70/R71*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*N145P/N250P/N260P*:rn*N145P/N250P/N260P*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*NF110/NF210/NF310*:rn*NF110/NF210/NF310*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*R530/R730*:rn*R530/R730*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*N150P/N210P/N220P*:rn*N150P/N210P/N220P*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*N150/N210/N220*:rn*N150/N210/N220*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*R519/R719*:rn*R519/R719*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*R518*:rn*R518*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*X360*:rn*X360*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*SQ45S70S*:rn*SQ45S70S*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*NC10*:rn*NC10*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*X120/X170*:rn*X120/X170*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*X125*:rn*X125*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*N130*:rn*N130*:
alias:          dmi*:svn*SAMSUNGELECTRONICSCO.,LTD.*:pn*N128*:rn*N128*:
depends:        rfkill
vermagic:       2.6.38.8-pclos3.pae SMP mod_unload modversions 686
parm:           force:Disable the DMI check and forces the driver to be loaded (bool)
parm:           debug:Debug enabled or not (bool)

I think you need to wait for a kernel update. You can also try to manually load the module, but I doubt it will work if it will not recognize your samsung model.

@davecs,
the N150 seems to be supported from this module ...

AS

[bicol_willem]

Thanks guys, at least the problem is recognized and obviously known of.

AS:
I was looking in the repo's for samsung-laptop (just wanted to try regardless) but could not find it. Is it out there any other place?
Not a biggy for likely we will have to wait for a new(er) kernel for comfort and ease.
Thanks again.

[AS]

Thanks guys, at least the problem is recognized and obviously known of.

AS:
I was looking in the repo's for samsung-laptop (just wanted to try regardless) but could not find it. Is it out there any other place?
Not a biggy for likely we will have to wait for a new(er) kernel for comfort and ease.
Thanks again.

samsung-laptop is a kernel module, simply (from root account) try the following command:
# modprobe samsung-laptop

if you don't get any error, check if module is properly loaded using:
# lsmod | grep samsung

the above command will not be permanent, the module will be lost on next reboot, but should be sufficient to perform some test.

[bicol_willem]

Ah, OK
First command returns: modprobe samsung-laptop
FATAL: Error inserting samsung_laptop (/lib/modules/2.6.38.8-pclos3.bfs/kernel/drivers/platform/x86/samsung-laptop.ko.gz): No such device

This thing here seems not supported?

Second command returns nothing ...
Guess that is "it" for now ..... (I meanwhile read not much good about the samsung module in newer kernels):  https://bugs.launchpad.net/ubuntu/+source/linux/+bug/810093

We better prepare for a longer wait......