No brightness adjustment on samsun n210 (Intel GMA 3150)

[calyth]

I've tried that GRUB config and it doesn't work.

[pramtung]

@wcale
Man, you really save me..
You are my hero. Your trick work on my laptop..

by the way, what is the f4.b thing, I don`t quite understand what's that for..

[wcale]

thanks

f4 is register address (= /sys/devices.../config offset) in hexadecimal. As you can see in program source, it just alters 244th byte. (f4 in hex = 244 dec)
.b tells setpci to change only one byte.

@lucas.andion
As far as I know, Fn+UP/DOWN are mapped by acpi. Because acpi doesn't recognise our laptop's acpi interface properly, it blocks these keys.

@calyth
Have you tried setpci method?

[mavdlind]

Hi there,
I tried the setpci trick but I get the following message:
Cannot open /sys/bus/pci/devices/0000:00:02.1/config

Any clues what to do next?
Cheers
mavdlind

[wcale]

There can be many reasons. First, are you doing it as root? Try

sudo setpci -s 00:02.0 f4.b=ff

Second thing - are you sure 00:02.1 is proper device address? I've checked it on two n210 and it was 00:02:0...

[mavdlind]

You're right, I made a confusion between two related devices....
Works brilliantly (no bad punt intended) now
Thanks
mavdlind

[fedira]

Hi,
you can adjust brightness level by sending values directly to device, by setpci:

setpci -s 00:02.0 f4.b=ff

where 00:02.0 is the device address returned by lspci,and ff is a hexadecimal value <0,ff>. I have n210 running Debian, works well

Wcale

Hi @wcale:

Thanks for providing this solution which seems to work for a number of people. I'd love to try it, but I need a little more info.

1. When I run

lspci

, which device address do I need? Display controller, or VGA-compatible controller?

2. I like to try to understand the commands I'm running before I run them. I get that

setpci -s 00:02.0

restricts the setpci utility to configure only devices within that domain. (I think.) What does

f4.b=ff

do? Is ff the brightest (like 00=black and ff=white)?

Thanks for your help!

[wcale]

Hi @fedira,
1. It's VGA compatible controller.
2. Yes. ff is the highest brightness level, 00 is brightness off. f4.b described in post #13

[yoyobeni]

@wcale
thanks a lot it was really helpful

[Jan Pieter]

Thanks wcale. The trick with
sudo setpci -s 00:02.0 f4.b=ff
worked for me too on my Samsung N210 with Ubuntu 10.4