Impossible to change screen brightness on iMac

[Ludovico Fischer]

Binary package hint: hal

On a imac(white) Core2Duo, ATIX1600, there is no way, using tools included with the distribution, to change the intensity of the LCD backlight. One has to use a program by Nicolas Boichat called bl1.c (which by the way seems to have stopped working with the present state of 8.04-Hardy). This is annoying as the screen defaults to max brightness, which many find quite blinding. This problem seems to affect all models of Intel iMacs and Macbooks. I wonder if there is a solution at kernel level somewhere?

See also bug 457882, the same problem on a MacBook.

[Steffen Röcker (sroecker)]

Please check if this has been fixed in Hardy now.

[Sebastian Urban (surban)]

This has not been fixed in Hardy with latest updates.

[Paolo Sammicheli (xdatap1)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue for you. Can you try with the latest Ubuntu release? Thanks in advance.

[i72Envp#hac (i72envphac)]

It is still an issue for me.

Ubuntu 9.10 64-bit version. iMac (Aluminum) model: MB325LL/A from early 2008.

[Paolo Sammicheli (xdatap1)]

Thanks for your answer.

[Xhacker Liu (xhacker)]

I am affected by this bug too. Please solve it!

[James Cameron (quozl)]

Also affected, on iMac11,1 27" i7 ATI M98L HD 4850 with Ubuntu 10.04 amd64. Have fglrx package installed. Backlight is turned off by DPMS idle timer fine. Backlight stays at a default brightness since boot despite DPMS activation. Backlight goes to maximum brightness on resume from suspend. Sunglasses or reboot are then required. xbacklight package ineffective. pommed package ineffective.

[Xhacker Liu (xhacker)]

This method can change the brightness.
http://www.felipe-alfaro.org/blog/2006/09/11/basic-backlight-support-for-macbook-pro/

Please fix the bug.

[Forrest Sheng Bao (forrest.bao)]

I wish this problem can be fixed soon. I hope to adjust screen brightness using my keyboard keys.

[dino99 (9d9)]

http://www.freedesktop.org/wiki/Software/hal/