Bug#164217: xserver-xfree86: [radeon] screen blanking never turns off the LCD backlight
> I doubt this is enough; RADEONDisplayPowerManagementSet() would also
> have to handle the various display types at least.
Then the code is incorrect in HEAD also, since there is still no
special handling there based on display type. A comment says that
additional handling for LCD might be needed, but says nothing about
DFP; and the checkin comment for radeon_driver.c 1.55 claims that it
adds DPMS for DFP.
But unfortunately it doesn't seem that this was actually the case.
This is disappointing.