Re: [PATCH] drm: of: fix leak of port_node

[kernel test robot]

Hi Tobias,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on drm-intel/for-linux-next]
[also build test WARNING on drm-tip/drm-tip drm-exynos/exynos-drm-next tegra-drm/drm/tegra/for-next linus/master v5.9-rc6 next-20200925]
[cannot apply to drm/drm-next]
[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/Tobias-Jordan/drm-of-fix-leak-of-port_node/20200926-063854
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: i386-randconfig-s001-20200925 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.2-201-g24bdaac6-dirty
        # https://github.com/0day-ci/linux/commit/9acba5320ef136e5d4a3b7563f4b5a362922c818
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Tobias-Jordan/drm-of-fix-leak-of-port_node/20200926-063854
        git checkout 9acba5320ef136e5d4a3b7563f4b5a362922c818
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 

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


sparse warnings: (new ones prefixed by >>)

>> drivers/gpu/drm/drm_of.c:318:37: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected struct device_node *node @@     got struct device_node const *port_node @@
>> drivers/gpu/drm/drm_of.c:318:37: sparse:     expected struct device_node *node
>> drivers/gpu/drm/drm_of.c:318:37: sparse:     got struct device_node const *port_node
   drivers/gpu/drm/drm_of.c:335:37: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected struct device_node *node @@     got struct device_node const *port_node @@
   drivers/gpu/drm/drm_of.c:335:37: sparse:     expected struct device_node *node
   drivers/gpu/drm/drm_of.c:335:37: sparse:     got struct device_node const *port_node

vim +318 drivers/gpu/drm/drm_of.c

   302	
   303	static int drm_of_lvds_get_remote_pixels_type(
   304				const struct device_node *port_node)
   305	{
   306		struct device_node *endpoint = NULL;
   307		int pixels_type = -EPIPE;
   308	
   309		for_each_child_of_node(port_node, endpoint) {
   310			struct device_node *remote_port;
   311			int current_pt;
   312	
   313			if (!of_node_name_eq(endpoint, "endpoint"))
   314				continue;
   315	
   316			remote_port = of_graph_get_remote_port(endpoint);
   317			if (!remote_port) {
 > 318				of_node_put(port_node);
   319				return -EPIPE;
   320			}
   321	
   322			current_pt = drm_of_lvds_get_port_pixels_type(remote_port);
   323			of_node_put(remote_port);
   324			if (pixels_type < 0)
   325				pixels_type = current_pt;
   326	
   327			/*
   328			 * Sanity check, ensure that all remote endpoints have the same
   329			 * pixel type. We may lift this restriction later if we need to
   330			 * support multiple sinks with different dual-link
   331			 * configurations by passing the endpoints explicitly to
   332			 * drm_of_lvds_get_dual_link_pixel_order().
   333			 */
   334			if (!current_pt || pixels_type != current_pt) {
   335				of_node_put(port_node);
   336				return -EINVAL;
   337			}
   338		}
   339	
   340		return pixels_type;
   341	}
   342	

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

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