@AMvis,

Int http://bbs.archlinux.org/viewtopic.php?pid=655144 apaige said on 5/11/2009 he was using NVIDIA driver 190.42.Fiveseven did not said which one he used.
That's all was said about the NVIDIA driver in this thread, I think.
I tried 4 NVIDIA drivers: 173, 185, 190 and 195.
All four looked stable for the time I used them, but the brightness issue had no visible difference, whatever any of these was used:
FN/UP&DOWN had no action on actual screen brightness, and I don't think we have yet any proof that the brightness issue is a driver issue or at least only a driver issue: in the archlinux thread nothing is said about modifying any driver (which is not possible as they are proprietary, so sources are not supposed to be available).
Have you the same understanding about this?
I use now the latest of the four tested, namely 195, following the wise advice of voRia, and no stability problem fsince it was installed.

@Julian2010
Yep I agree with you on the nvidia drivers, i've tried 185, 190 and 195 versions too with no luck. If i get time I might start looking at the kernel source looking for 2.6.31.19.32 see if I can find the bits on the archlinux forum.

For the wifi I used the realtek driver from voRia's repository (you rock dude!), works fine apart from when laptop goes to sleep.
You can get it to come back after sleep by editing /usr/lib/pm-utils/sleep.d/55NetworkManager with:


Which I stole from this forum somewhere.

I'll keep lurking here hopefully someone smarter than me will solve the brightness issue before i loose hope.

The 'samsung-wireless' package takes care to install a power manager script, which removes the wireless module on suspend/hibernation. So, the manual modification to '/usr/lib/pm-utils/sleep.d/55NetworkManager' should not be necessary anymore.

Just to be sure I did not miss something:
I added in the GRUB command line backlight_control=video instead of = vendor, as you mentioned only these two values are available for this variable.Updated GRUB &rebooted.
It works as with quiet splash only in that command line:
FN/UP&DOWN make the brightness bubble appear and its index change, but with no effect on the actual screen brightness;
So, as expected, refering to your explanation about the acpi_backlight variable and its default value when not specified.

@ voRia:
About the N510 brightness control issue:
What we know:
-The /proc/acpi/video/IGPU/LCD0 file exists, is not empty.The value inside it can be echoed and modified, without effect on the actual screen brightness.
-The Fn/UP&DOWN keys do change in the same way the the current value contained in /proc/acpi/video/IGPU/LCD0, also without effect on the actual screen brightness.
-The gnome brightness applet does not work (shows red, "impossible to read the screen actual brightness").

Enclosed is the Xorg.0.log file.
Is there in this log anything related to display and/or driver that might help to understand why the /proc/acpi/video/IGPU/LCD0 file&value are not opened&used?

As a newbie, the only things I could notice in this log:

-|-->Screen "Default Screen" (0)
(**) | |-->Monitor "<default monitor>"
(==) No device specified for screen "Default Screen".
Using the first device section listed.
(**) | |-->Device "Default Device"
(==) No monitor specified for screen "Default Screen".
Using a default monitor configuration.
/.../
(--) Feb 21 13:01:33 NVIDIA(0): Connected display device(s) on ION LE at PCI:2:0:0:
(--) Feb 21 13:01:33 NVIDIA(0): Seiko (DFP-0)
/../
(II) Feb 21 13:01:33 NVIDIA(0): Assigned Display Device: DFP-0
/../
(II) Feb 21 13:01:34 NVIDIA(0): ACPI display change hotkey events enabled: the X server is new
(II) Feb 21 13:01:34 NVIDIA(0): enough to receive ACPI display change hotkey events.

I understand that at boot the NVIDIA driver chooses ( by default?) a "DFP0" display device , so not "LCD0".
I am not able to understand if this a fixed value, a default one which might be changed somewhere and so on, and even if "DFP0" is really different from "LCD0".
And in the /proc/acpi/video/IGPU there is no DFP0 sub-folder (only LCD0, DSP0, CRT0,HDMI)
Could all this explain why the LCD0 value is never used and does it give you any hint about what is (not) happening?
By the way, what is your understanding of the archlinux report about N510 brightness, I mean, what was the purpose ( in" simple words" only..) of the patch someone made there?
Thanks.

I just forgot in the previous message the /etc/X11/xorg.conf content:

Section "Screen"
Identifier "Default Screen"
DefaultDepth 24
EndSection

Section "Module"
Load "glx"
EndSection

Section "Device"
Identifier "Default Device"
Driver "nvidia"
Option "NoLogo" "True"
EndSection

I think the "DFP-0" value reported in the xorg log and the "LCD0" directory in '/proc/acpi/video/IGPU' are not related in any way.
That's the problem, I don't understand.
The patch posted there is extracted by the ubuntu kernel, and lets the backlight/brightness to be found (and presumably, controlled). The fact is that you are already using it, since you are using ubuntu.
I can't see nothing, apart of this:
Try to add to your '/etc/X11/xorg.conf' the option:
This should change the way the display hotkeys are used.
So, according to your posted 'xorg.conf', change it this way:
Be sure to reboot in order to apply the change.

Hi voRia,

I added
Option "EnableACPIHotkeys" "false"
in the xorg.conf file and rebooted.
It did not change anything to the lack of actual brightness control, meaning the Fn/UP&DOWN let the brightness bubble appear and change the index it shows., but nothing else.
So, I am wondering if " EnableACPIHotkey" is ever used , as be it "true" (when not specified) or "false" (when added in xorg.conf) does not change anything to the working of all Fn/Fx & Fn/UP&DOWN keys.
All this becomes really puzzling.....and I am even wondering if the so-called patch refered to in the Archlinux bug already mentioned is really part of my installation!
By the way, in my /var/log/dmesg file:
0.216278] [Firmware Bug]: ACPI: ACPI brightness control misses _BQC function
for which I suppose the "Archlinux patch "is a workaround.
It seems that the real brightness (in fact it should be called the backlight level, as "brightness " in the nvidia settingsr color correction tab is really something else ) as it is during the grub screen (where it can be only be changed with the hotkeys) is not later (during boot itself and/or later on) read, so any modification to an un-read data cannot be applied (that's maybe why the gnome applet complains about actual screen brightness not readable).
Looking around on some forums, people discussed a BACKLIGHT_CONTROL variable which was not initialized (I do not remember if it was about some Toshiba or Sony laptops, but I can find it again),
Is there any way to see in my system the status of that data :if it exists, if it is associated or not with a screen/display and so on?
I ask this because in terminal the xbacklight command always answers "No outputs have backlight properties", whatever modifications you advised me to do I tried.
Thank you.

@voRia,

It may be that the N510 brightness issue is on its way , so , for the time being, do not waste your time about it and with my last message.
I will keep you informed in due time of the results (whatever they will be), meaning by this: when I get enough time to try a few things I discussed with other people.

@Julian

Good news my friend, had to reinstall ubuntu today (to much messing about trying to fix things). Went for the latest daily build, burned iso, installed, and let ubuntu put the recommended nvidia drivers on.

Pulled the power from the laptop & the screen dimmed!!!!! Also responds to


I'll post more details when I have them
AMvis

I'm currently running...
kernel image- 2.6.32.15.16
nvidia driver- 195.63.03-0ubuntu1
None of voRias packages yet, as the repo wasn't working.

@voRia
Is the repo OK to use on Lucid? Can I get just change the distribution to "karmic" after adding your repo to my software sources?

The brightness up and down keys aren't doing anything, not event the "bubble" display comes up but volume does and works. Some of the samsung function keys work but not all, Numlock, sleep, mute do but rest don't. No wifi till i get samsung-wireless package installed

No, the repository does not work with lucid.
The only package that may work is 'samsung-scripts', but I have not tried it yet so I'm not sure.

Regarding the FN keys, they probably need to be enabled, but things have changed a little bit in lucid so I can't give you instructions right now. I will do it, as soon as I have a chance to install it.

@AMvis:

Nice to read you made it in the end!
Luckily my lack of knowledge prevents me to mess up my installation trying to make changes I am not able to manage properly, and as I am not really fond of installing again Ubuntu...
So I stay with the 2.6.31-19 kernel from voRia's repository..the more as the brightness problem is now solved on my machine.
Following discussions with other people -live discussions I mean there - I went on the SAMSUNG support site and discovered that since 3 Feb. 2010 a new BIOS was available: 03MU , instead of 02MU which came withe the N510.
I could not find any information about the changes that SAMSUNG techs. have done in this new BIOS.
As I still keep WInXP on my machine (double boot in the grub), I decided [reluctantly] to upgrade the BIOS as it looked quite easy to do as described in the SAMSUNG BIOS update page.
BIOS updated itself without any trouble to the 03MU version, and I set its parameters as they were before in the previous BIOS.
And here is the change:
Now, Fn/UP&DOWN keys do change the actual screen brightness.
And when the AC adapter is unplugged or plugged, brightness changes accordingly to the settings made in System/Preferences/PowerManagement.
So it seems the BIOS update sorted out the things.
Strangely, in a terminal, xbacklight command still answers "no output has backlight property"..although obviously the LCD screen has backlight property, but nothing is perfect.I did not even test the cat or echo commands in .../LCD0/brightness, as the Fn/UP&DOWN do now what is expected from them.

@voRia
I do not know if the new BIOS has changed anything for the unassigned Fn/Fx keys and/or for the related lack of key-release events, but if anything has been changed there, the changes you made specifically in the kernel are compatible with the new BIOS: maybe these problems are corrected "twice" now, but who cares?

Stangely the BIOS update messed up something in the WIFI which would not start at all.
The only way I found to have it work again was to de-activate in Compiz/Commands the line related to the Fn/F9, but I have still to right-click twice on the taskbar WIFI bargraph/"activate the wireless network" to get it work, as it never starts au tomatically the connexion: although at start the "activate the wireless network" is actually ticked, nothing happens: I need to untick it then tick it again, and the WIFI link comes up.
That's not a real problem, but it's a bit odd however as before the WIFI link started right away after start.
Maybe they changed something in the BIOS related to the Fn/F9 which comes in conflict with sthg about this key combination in the samsung-script, but this is only a guess.

On an X120 here (05CX BIOS).
I can get the function keys to bind to the brightness widget after installing from your repository, but under no circumstances have I been able to change the brightness of the backlight (even using the gnome widget directly).
I even tried the "echo 55 | tee -a brightness" method on /proc/acpi/video/GFX0/DD04 (there seem to be DD00-DD05 I cannot cat brightness in any other folder), it sets it successfully but nothing happens.

Any ideas?

So, this was the problem, buggy BIOS... I should have been thought about it.

I don't think so. If this new BIOS for N510 has just fixed backlight control by exposing it to userspace (in other way, enabling it to be controlled) as it happened with the latest BIOS for NC10, yet you need fixed packages from my repository.

Please check in your BIOS, probably the wireless initial status is disabled.