Hi Andy,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   7ddd09fc4b745fb1d8942f95389583e08412e0cd
commit: 4a34a9dcec9405e29a0ad7f56400581fbd780691 [4137/5337] drm/drm_panel: Fix EXPORT of drm_panel_of_backlight() one more time
config: i386-randconfig-b003-20191226 (attached as .config)
compiler: gcc-7 (Debian 7.5.0-3) 7.5.0
reproduce:
        git checkout 4a34a9dcec9405e29a0ad7f56400581fbd780691
        # save the attached .config to linux build tree
        make ARCH=i386 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-sitronix-st7701.ko] undefined!
   ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-seiko-43wvf1g.ko] undefined!
   ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-raydium-rm68200.ko] undefined!
   ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.ko] undefined!
   ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-olimex-lcd-olinuxino.ko] undefined!
   ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-innolux-p079zca.ko] undefined!
   ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-simple.ko] undefined!
   ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-lvds.ko] undefined!

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