Brightness change not working on Samsung R780

[Fetus]

Hey there.

I installed Sabayon today but changing the backlight is not working.

Using the FN-Keys, the backlight-info thing shows up however the backlight doesn't change the brightness.

I can turn it off completely using the samsung-tools hotkey, but that's about it.

Other packages I have installed besides samsung-tools:

nvidiabl-07.2#3.2.0-sabayon

Adding acpi_backlight=vendor doesn't help either.

Any ideas?

[Fitzcarraldo]

I don't have your hardware, so I can only make suggestions.

What exactly do you have in the kernel boot line in /boot/grub/grub.cfg? Have you tried adding both of the following boot parameters to the kernel boot line?:

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acpi_osi=linux acpi_backlight=vendor

In an Ubuntu Forums post giving a solution to the Samsung R780 brightness, the poster mentions that, apart from the above two kernel boot parameters, he also had to add the following line to the file /etc/modules:

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nvidia_bl max_level=0x1ffff shift=11

Now. the Gentoo/SL equivalent of Ubuntu's /etc/modules in this case would be /etc/modprobe.d/nvidia_bl.conf (I'm assuming that the module is named nvidia_bl in Gentoo, but see if you can find the file nvidia_bl.ko to confirm that) and the contents would presumably be:

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options nvidia_bl max_level=0x1ffff shift=11

Then you'd have to run the command update-modules as root user in a Konsole/Terminal window, reboot and see if there is a difference.

[Fetus]

I tried adding both acpi_osu=linux and acpi_backlight=vendor, yes. Didn't do much.

But I will certainly try the Nvidia bit later today, thank you!

EDIT:

Alright, so I've searched and found a nvidiabl.ko, created a nvidiabl.conf and put your options in there, rebootet but no change.

I can move the display slider around but nothing happens.

[Fitzcarraldo]

Right, well let's see what else Google throws up, then. Try the fix in Comment #2 in Ubuntu Bugzilla Bug Report #693494:

Edit the file /lib/udev/rules.d/95-keyboard-force-release.rules and add the following line:

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ENV{DMI_VENDOR}=="[sS][aA][mM][sS][uU][nN][gG]*", ATTR{[dmi/id]product_name}=="*E252*|*N120*|*N128*|*N130*|*N140*|*N148/N208*|*N148P/N208P/N218P/NB28P*|*N150*|*N150/N210/N220*|*N220*|*N308*|*N310*|*N510*|*NB30*|*NC10/N110*|*ND10*|*NF110/NF210/NF310*|*P580*|*Q210/P210*|*Q330*|*Q430/Q530*|*R410P*|*R420/R470*|*R425/R525*|*R428/P428*|*R460*|*R463*|*R468/R418*|*R480/R431/R481*|*R505*|*R509*|*R510/P510*|*R518*|*R519/R719*|*R520/R522/R620*|*R528/R728*|*R530/R730*|*R530/R730/P590*|*R560*|*R580*|*R580/R590*|*R59/R60/R61*|*R59P/R60P/R61P*|*R710*|*R720*|*R780/R778*|*RF510/RF410/RF710*|*SR58P*|*SR700*|*SR70S/SR71S*|*SX22S*|*X118*|*X120*|*X460*", RUN+="keyboard-force-release.sh $devpath samsung-other"

then reboot.

I see your model number in that line, so keep your fingers crossed. I would leave both the other changes (the two additions to the kernel boot line, plus the two options for the nvidiabl module) still applied.

By the way, when you use the command lsmod as root user in a Konsole/Terminal window, do you see that module nvidiabl loaded, and with that specific name? Please check that too.