ERROR: "radeon_legacy_set_backlight_level" [drivers/gpu/drm/radeon/radeon.ko]

Hi Alex,

FYI, kernel build failed on

tree:   git://people.freedesktop.org/~airlied/linux.git drm-next
head:   268d28371cd326be4dfcd7eba5917bf4b9d30c8f
commit: 37e9b6a62fb775276f8edb5bd2b9f13a3102b9dd [148/301] drm/radeon: rework the backlight control to be an asic callback
config: ia64-defconfig

All error/warnings:

ERROR: "atombios_set_backlight_level" [drivers/gpu/drm/radeon/radeon.ko] undefined!
ERROR: "radeon_legacy_set_backlight_level" [drivers/gpu/drm/radeon/radeon.ko] undefined!
ERROR: "backlight_force_update" [drivers/gpu/drm/radeon/radeon.ko] undefined!

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0-DAY kernel build testing backend Open Source Technology Center
Fengguang Wu, Yuanhan Liu Intel Corporation