Hi Hans,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v5.8-rc4]
[cannot apply to drm-intel/for-linux-next drm-tip/drm-tip next-20200708]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Hans-de-Goede/drm-Add-privacy-screen-class-and-connector-properties/20200709-004703
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git dcde237b9b0eb1d19306e6f48c0a4e058907619f
config: i386-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-14) 9.3.0
reproduce (this is a W=1 build):
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

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/platform/x86/thinkpad_acpi.c:9707:5: warning: no previous prototype for 'lcdshadow_set_sw_state' [-Wmissing-prototypes]
    9707 | int lcdshadow_set_sw_state(struct drm_privacy_screen *priv,
         |     ^~~~~~~~~~~~~~~~~~~~~~
>> drivers/platform/x86/thinkpad_acpi.c:9722:6: warning: no previous prototype for 'lcdshadow_get_hw_state' [-Wmissing-prototypes]
    9722 | void lcdshadow_get_hw_state(struct drm_privacy_screen *priv)
         |      ^~~~~~~~~~~~~~~~~~~~~~

vim +/lcdshadow_set_sw_state +9707 drivers/platform/x86/thinkpad_acpi.c

  9706	
> 9707	int lcdshadow_set_sw_state(struct drm_privacy_screen *priv,
  9708				   enum drm_privacy_screen_status state)
  9709	{
  9710		int output;
  9711	
  9712		if (WARN_ON(!mutex_is_locked(&priv->lock)))
  9713			return -EIO;
  9714	
  9715		if (!acpi_evalf(lcdshadow_set_handle, &output, NULL, "dd", (int)state))
  9716			return -EIO;
  9717	
  9718		priv->hw_state = priv->sw_state = state;
  9719		return 0;
  9720	}
  9721	
> 9722	void lcdshadow_get_hw_state(struct drm_privacy_screen *priv)
  9723	{
  9724		int output;
  9725	
  9726		if (!acpi_evalf(lcdshadow_get_handle, &output, NULL, "dd", 0))
  9727			return;
  9728	
  9729		priv->hw_state = priv->sw_state = output & 0x1;
  9730	}
  9731	

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