drivers/gpu/drm/i915/display/intel_gmbus.c:144:6: warning: no previous prototype for 'intel_gmbus_ddc_reserve_for_mipi'

[kernel test robot]

tree:   https://github.com/0day-ci/linux/commits/UPDATE-20210916-220656/Lee-Shawn-C/drm-i915-dsi-unregister-gmbus-if-LFP-display-was-MIPI-panel/20210916-181936
head:   37a6b71c76cc745b62b40e77e7f882ff7ceeadb0
commit: 37a6b71c76cc745b62b40e77e7f882ff7ceeadb0 drm/i915/dsi: do not register gmbus if it was reserved for MIPI display
date:   7 hours ago
config: x86_64-randconfig-a015-20210916 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/37a6b71c76cc745b62b40e77e7f882ff7ceeadb0
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review UPDATE-20210916-220656/Lee-Shawn-C/drm-i915-dsi-unregister-gmbus-if-LFP-display-was-MIPI-panel/20210916-181936
        git checkout 37a6b71c76cc745b62b40e77e7f882ff7ceeadb0
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

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

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/i915/display/intel_gmbus.c:144:6: warning: no previous prototype for 'intel_gmbus_ddc_reserve_for_mipi' [-Wmissing-prototypes]
     144 | bool intel_gmbus_ddc_reserve_for_mipi(struct drm_i915_private *dev_priv,
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/intel_gmbus_ddc_reserve_for_mipi +144 drivers/gpu/drm/i915/display/intel_gmbus.c

   143	
 > 144	bool intel_gmbus_ddc_reserve_for_mipi(struct drm_i915_private *dev_priv,
   145					      unsigned int pin)
   146	{
   147		enum port port;
   148	
   149		if (intel_bios_is_dsi_present(dev_priv, &port)) {
   150			if (DISPLAY_VER(dev_priv) >= 11) {
   151				if ((pin == GMBUS_PIN_2_BXT && dev_priv->vbt.dsi.config->dual_link) ||
   152				     pin == GMBUS_PIN_1_BXT)
   153					return true;
   154			}
   155		}
   156	
   157		return false;
   158	}
   159	

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

Attachment: .config.gz
Description: application/gzip