Hi Daniel,

[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on linus/master]
[also build test WARNING on sparc-next/master v5.9-rc5 next-20200916]
[cannot apply to linuxtv-media/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Daniel-Scally/Add-bridge-driver-to-connect-sensors-to-CIO2-device-via-software-nodes-on-ACPI-platforms/20200917-053714
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5925fa68fe8244651b3f78a88c4af99190a88f0d
config: x86_64-randconfig-a013-20200916 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 9e3842d60351f986d77dfe0a94f76e4fd895f188)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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

All warnings (new ones prefixed by >>):

>> drivers/media/pci/intel/ipu3/ipu3-cio2.c:1746:6: warning: no previous prototype for function 'cio2_sync_state' [-Wmissing-prototypes]
   void cio2_sync_state(struct device *dev)
        ^
   drivers/media/pci/intel/ipu3/ipu3-cio2.c:1746:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void cio2_sync_state(struct device *dev)
   ^
   static 
   1 warning generated.

# https://github.com/0day-ci/linux/commit/d8d13ef927def4ddc8948d05ba7c606253a1e1df
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Daniel-Scally/Add-bridge-driver-to-connect-sensors-to-CIO2-device-via-software-nodes-on-ACPI-platforms/20200917-053714
git checkout d8d13ef927def4ddc8948d05ba7c606253a1e1df
vim +/cio2_sync_state +1746 drivers/media/pci/intel/ipu3/ipu3-cio2.c

  1745	
> 1746	void cio2_sync_state(struct device *dev)
  1747	{
  1748		struct cio2_device *cio2;
  1749		int ret = 0;
  1750	
  1751		if (IS_ENABLED(CONFIG_ACPI)) {
  1752			cio2 = dev_get_drvdata(dev);
  1753	
  1754			if (!cio2) {
  1755				dev_err(dev, "Failed to retrieve driver data\n");
  1756				return;
  1757			}
  1758	
  1759			/* insert the bridge driver to connect sensors via software nodes */
  1760			ret = request_module("cio2-bridge");
  1761	
  1762			if (ret)
  1763				dev_err(dev, "Failed to insert cio2-bridge\n");
  1764	
  1765			ret = cio2_parse_firmware(cio2);
  1766	
  1767			if (ret) {
  1768				v4l2_async_notifier_unregister(&cio2->notifier);
  1769				v4l2_async_notifier_cleanup(&cio2->notifier);
  1770				cio2_queues_exit(cio2);
  1771			}
  1772		}
  1773	}
  1774	

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