Hi Tian,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on next-20200305]
[cannot apply to linus/master v5.6-rc4 v5.6-rc3 v5.6-rc2 v5.6-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Tian-Tao/drm-hisilicon-Add-the-load-and-unload-for-hibmc_driver/20200306-150600
base:    47466dcf84ee66a973ea7d2fca7e582fe9328932
config: arm64-defconfig (attached as .config)
compiler: aarch64-linux-gcc (GCC) 7.5.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.5.0 make.cross ARCH=arm64 

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

All warnings (new ones prefixed by >>):

   drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c: In function 'hibmc_unload':
>> drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c:280:9: warning: 'return' with a value, in function returning void
     return 0;
            ^
   drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c:265:6: note: declared here
    void hibmc_unload(struct drm_device *dev)
         ^~~~~~~~~~~~
   drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c: In function 'hibmc_pci_probe':
   drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c:345:21: warning: unused variable 'dev' [-Wunused-variable]
     struct drm_device *dev;
                        ^~~

vim +/return +280 drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c

5e0df3a08f3d17 Rongrong Zou  2016-11-16  264  
da3ad5dfcca37d Tian Tao      2020-03-06  265  void hibmc_unload(struct drm_device *dev)
5e0df3a08f3d17 Rongrong Zou  2016-11-16  266  {
e4daebc77e7b34 Rongrong Zou  2016-11-16  267  	struct hibmc_drm_private *priv = dev->dev_private;
e4daebc77e7b34 Rongrong Zou  2016-11-16  268  
b3df5e65cc0369 Daniel Vetter 2017-06-21  269  	drm_atomic_helper_shutdown(dev);
b3df5e65cc0369 Daniel Vetter 2017-06-21  270  
1d98b91611725e Rongrong Zou  2016-11-16  271  	if (dev->irq_enabled)
1d98b91611725e Rongrong Zou  2016-11-16  272  		drm_irq_uninstall(dev);
1d98b91611725e Rongrong Zou  2016-11-16  273  	if (priv->msi_enabled)
1d98b91611725e Rongrong Zou  2016-11-16  274  		pci_disable_msi(dev->pdev);
1d98b91611725e Rongrong Zou  2016-11-16  275  
da52605eea8f2c Rongrong Zou  2016-11-16  276  	hibmc_kms_fini(priv);
e4daebc77e7b34 Rongrong Zou  2016-11-16  277  	hibmc_mm_fini(priv);
da3ad5dfcca37d Tian Tao      2020-03-06  278  	hibmc_hw_unmap(priv);
e4daebc77e7b34 Rongrong Zou  2016-11-16  279  	dev->dev_private = NULL;
5e0df3a08f3d17 Rongrong Zou  2016-11-16 @280  	return 0;
5e0df3a08f3d17 Rongrong Zou  2016-11-16  281  }
5e0df3a08f3d17 Rongrong Zou  2016-11-16  282  

:::::: The code at line 280 was first introduced by commit
:::::: 5e0df3a08f3d17485a5081634902424c6834e001 drm/hisilicon/hibmc: Add hisilicon hibmc drm master driver

:::::: TO: Rongrong Zou <zourongrong@gmail.com>
:::::: CC: Rongrong Zou <zourongrong@gmail.com>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org