Firmware Bug: ACPI No _BCQ method
Submitted by Cedric Sodhi
Assigned to xf86-video-ati maintainers
Radeon Device aa68 Graphics card (Cedar). Used in hybrid graphics with Intel i915 vgaswitcheroo, hence both are compiled in (Bug #36783 ) and KMS enabled (without KMS the problem usually not occurs). On boot, the screen tunrs of the backlight by itsself and has to be turned on manually. A message in dmesg that is likely to be related says
Firmware Bug: ACPI: No _BCQ method
THe log has several errors related to the radeon. Kernel is 39-rc5.