[REGRESSION?] Blanking screen does not blank it on Radeon HD3200 (Thinkpad Edge 13, model 0197)

[Yaroslav Fedevych]

In text mode, instead of blanking the screen and shutting it down, it
is instead painted white, backlight going full steam.

I have bisected the code and git tells me the first bad commit is
f3728734ba78310525bf4a361c7787c7c6fa5d40.

Apparently my laptop, despite having atom tables, still needs legacy
backlight controls. Or whatever.

----------------------------------------------------------
drm/radeon: add backlight control for atom devices (v2)

On systems that use the build in GPU backlight controller,
we can use atom tables to change the brightness level.

v2: use firmware flags
----------------------------------------------------------

And the details at

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=f3728734ba78310525bf4a361c7787c7c6fa5d40

I was first enthusiastic about using some textmode goodness, but
unfortunately have to return to X11, under it everything works okay,
strange but true.