Re: [PATCH] drm/of: Fix device node reference leak in drm_of_panel_bridge_remove

[kernel test robot <lkp@intel.com>]

Hi Miaoqian,

kernel test robot noticed the following build errors:

[auto build test ERROR on drm-misc/drm-misc-next]
[also build test ERROR on linus/master v6.18-rc3 next-20251028]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Miaoqian-Lin/drm-of-Fix-device-node-reference-leak-in-drm_of_panel_bridge_remove/20251028-141134
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20251028060918.65688-1-linmq006%40gmail.com
patch subject: [PATCH] drm/of: Fix device node reference leak in drm_of_panel_bridge_remove
config: mips-randconfig-r072-20251028 (https://download.01.org/0day-ci/archive/20251028/202510282123.AjUbRs11-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project e1ae12640102fd2b05bc567243580f90acb1135f)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251028/202510282123.AjUbRs11-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202510282123.AjUbRs11-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/gpu/drm/drm_bridge.c:37:
>> include/drm/drm_of.h:174:2: error: call to undeclared function 'of_node_put'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     174 |         of_node_put(remote);
         |         ^
   1 error generated.
--
   In file included from drivers/gpu/drm/panel/panel-magnachip-d53e6ea8966.c:10:
>> include/drm/drm_of.h:174:2: error: call to undeclared function 'of_node_put'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     174 |         of_node_put(remote);
         |         ^
   In file included from drivers/gpu/drm/panel/panel-magnachip-d53e6ea8966.c:13:
   In file included from include/linux/backlight.h:13:
   In file included from include/linux/fb.h:5:
   In file included from include/uapi/linux/fb.h:6:
   In file included from include/linux/i2c.h:21:
   In file included from include/linux/irqdomain.h:14:
>> include/linux/of.h:129:13: error: conflicting types for 'of_node_put'
     129 | extern void of_node_put(struct device_node *node);
         |             ^
   include/drm/drm_of.h:174:2: note: previous implicit declaration is here
     174 |         of_node_put(remote);
         |         ^
   2 errors generated.


vim +/of_node_put +174 include/drm/drm_of.h

   153	
   154	/*
   155	 * drm_of_panel_bridge_remove - remove panel bridge
   156	 * @np: device tree node containing panel bridge output ports
   157	 *
   158	 * Remove the panel bridge of a given DT node's port and endpoint number
   159	 *
   160	 * Returns zero if successful, or one of the standard error codes if it fails.
   161	 */
   162	static inline int drm_of_panel_bridge_remove(const struct device_node *np,
   163						     int port, int endpoint)
   164	{
   165	#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_DRM_PANEL_BRIDGE)
   166		struct drm_bridge *bridge;
   167		struct device_node *remote;
   168	
   169		remote = of_graph_get_remote_node(np, port, endpoint);
   170		if (!remote)
   171			return -ENODEV;
   172	
   173		bridge = of_drm_find_bridge(remote);
 > 174		of_node_put(remote);
   175		drm_panel_bridge_remove(bridge);
   176	
   177		return 0;
   178	#else
   179		return -EINVAL;
   180	#endif
   181	}
   182	

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