Red Hat Bugzilla – Bug 115218
Laptop LCD backlight doesn't turn off on ATI Radeon chips
Last modified: 2007-11-30 17:10:36 EST
Description of problem: My laptop contains an ATI Radeon Mobility 7500 graphics card. This card is supposed to be supported with Xfree86 4.3, but I can't manage to switch the screen off: > xset -display :0 dpms force off The screen gets black, but not switched off (backlighting is still on). Version-Release number of selected component (if applicable): XFree86-4.3.0-42 How reproducible: Always Steps to Reproduce: 1. xset -display :0 dpms force off 2. 3. Actual results: The screen gets black, but not switched off (backlighting is still on). Expected results: The LCD panel backlight turns off. Additional info: There is a solution for this problem in the XFree86 CVS. See http://michaelo.free.fr/contrib/radeon/poweroff.php3 for details.
This isn't a bug really, the XFree86 4.3.0 driver just does not support this 'feature' of the Radeon hardware. While the current CVS code does support it, none of the links on the bug report nor the URL you provided contain a _proper_ minimal unified diff to add this support to the driver. The patch referenced in the bug report is a series of things committed to CVS all in one shot, and does not actually have a link to the patch. I'd have to manually dig this out of CVS myself. While I don't mind doing that, it is a low priority since it is for adding a new feature rather than fixing a bug. So I'll leave this open for now until I have time to dig the patch out of CVS and review it, backport it to 4.3.0 and have it tested. If anyone is interested in having this happen sooner rather than later, they're welcome to poke through XFree86 CVS and backport the patch themselves and attach it to the bug report. That would speed things up.
I just realized I have this problem too on my IBM Thinkpad T41. Adding this to my TODO list.
The move from XFree86-4.3.0 to xorg-x11 in rawhide solved this problem!