* Linus Torvalds -- Wednesday 27 April 2011:
Go forth and test,
Doesn't work on my notebook with i915/KMS. But then again, neither did 2.6.38 or any of its stable releases. The last working version was 2.6.38-rc8. The problem has been reported[1], but the bug got closed in the wrong assumption that the bug is fixed. I reported that, too. No reactions to that.
The bug was introduced with commit ba3820ade317ee36e496b9b40d2ec3987dd4aef0 by Takashi Iwai. The result is that when using KMS my notebook's[2] screen remains dark, because the backlight isn't turned on.
Reverting commit ba3820ade317ee36e496b9b40d2ec3987dd4aef0 makes my notebook work correctly again as it used to in 2.6.38-rc8 and before.
m.
[1] https://bugzilla.kernel.org/show_bug.cgi?id=31522 [2] Acer TravelMate 5735Z-452G32Mnss, using Intel GM45