MacBook(Pro) with Nvidia graphics adapter display backlight fix call for testing

[bryonak]

Confirming that this works on a MacbookPro 3.1.
No problems with low values either (the float rounding issue hyperboloid mentioned)

Keep up the good work!

[_mario_]

Hi,

One small problem: When the brightness is very low, one encounters a black screen upon resume, and at that point (before password verification) the brightness controls are disabled, so one must enter the password blindly and then use the controls to manually up the display brightness.

This seems like a rounding issue with a floating point variable, although I have not tried to look at the code. Anyway, perhaps a minimum threshold should be something non-zero so that the display will never come back completely black, which is disconcerting.

that's interesting. the brightness values are indeed integral values. there's no floating point at all. and on my machine the brightness keys work during this login window. (not the GDM chooser, but a lock screen.)

By the way, the suggested code in step 2

sudo echo 1 > /sys/class/backlight/mbp_backlight/brightness

does not work for me - it gives me back "permission denied" even though I did not forget the "sudo" prefix. Very strange. Anyway, I set the brightness using the manual control F1-F2.

sorry. my fault. (I usually prefer to use a root shell instead.) I'm going to write it correctly next time. I also edited my initial post according to the changes proposed in the forum.

Good work, Mario. Can you similarly figure out a way to make it remember the KEYBOARD backlight settings after suspend/reboot?

probably not. keyboard backlight is something completely different.

ciao,
Mario

[Nikos.Alexandris]

Hi all,
[...]
3. MacBook 5 and MacBookPro 5 users: This might also work for the new 5th generation models. I don't have these machines and thus cannot test it. Please check out this driver and report whether it works at all.
[...]
thanks & ciao,
Mario

Sorry Mario, it does not work for me (MBP5)

[hyperboloid]

One small problem: When the brightness is very low, one encounters a black screen upon resume, and at that point (before password verification) the brightness controls are disabled, so one must enter the password blindly and then use the controls to manually up the display brightness.

More info on the above. The reported screen blanking behavior was caused by interference from testing the light sensors; see the thread: http://ubuntuforums.org/showthread.php?p=6148340. I had uncommented the commented code in /usr/share/hal/fdi/information/10freedesktop/10-applesmc.fdi. Somehow that seems to have caused the screen to blank on resume after suspend, but only when the display was set to its lowest brightness setting: 1. Anyway, once I reverted that fdi file back to its original version, with the light sensor stuff commented out, the screen blanking issue went away, even on the lowest brightness setting.

In short, it seems that mario's fix works fine on my MBP 4,1. By the way, this is just for a suspend/resume. The fix has no effect on a cold boot. In the case of a boot, the previous display brightness settings are not remembered. I'm assuming this is the intended behavior.

[druggo]

I can confirm that this is not working on MB 5,1 let me know if you wan't to try something else that might fix it mario.

Regards

[cllgnc89]

Thanks, Great Work!

[Nikos.Alexandris]

I don't know who, what and how fixed the suspend issue. I got now the nvidia driver 177.80 and suspend does not take so long any more, keyboard backlight is adjusted when (un-)plugging the AC power supply cable, dual head works (twinview and xinerama, with rotation as well). Unfortunately brightness regulation does not work.

Cheers, Nikos

[linuxbest]

after half day reserved with apple driver for windows xp, I geting the brightness control works in linux with Macbook5,1. Hope the driver will good works in all intel base mac book.

I put the source code here:
http://bj.soulinfo.com/~hugang/mac5_1/bl/

Issue:
echo 1 > /sys/class/backlight/mbp_backlight/brightness
I using NVIDIA xorg driver, I must switch back to text mode, doing echo, in x11 echo change nothing.

[linuxbest]

after half day reserved with apple driver for windows xp, I geting the brightness control works in linux with Macbook5,1. Hope the driver will good works in all intel base mac book.

I put the source code here:
http://bj.soulinfo.com/~hugang/mac5_1/bl/

Issue:
echo 1 > /sys/class/backlight/mbp_backlight/brightness
I using NVIDIA xorg driver, I must switch back to text mode, doing echo, in x11 echo change nothing.

[ercoppa]

First of all, thanks for the hard work!

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