Hi Andy,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   2019fc96af228b412bdb2e8e0ad4b1fc12046a51
commit: 4a34a9dcec9405e29a0ad7f56400581fbd780691 drm/drm_panel: Fix EXPORT of drm_panel_of_backlight() one more time
date:   8 weeks ago
config: i386-randconfig-c002-20200215 (attached as .config)
compiler: gcc-7 (Debian 7.5.0-4) 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-sharp-lq101r1sx01.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-ronbo-rb070d30.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-simple.ko] undefined!
>> ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-lvds.ko] undefined!
>> ERROR: "drm_panel_of_backlight" [drivers/gpu/drm/panel/panel-boe-himax8279d.ko] undefined!

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0-DAY CI Kernel Test Service, Intel Corporation
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