Re: [PATCH v7 2/4] drm/bridge: add lvds controller support for sam9x7

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

Hi Dharma,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on linus/master v6.9-rc4 next-20240419]
[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/Dharma-Balasubiramani/dt-bindings-display-bridge-add-sam9x75-lvds-binding/20240418-170157
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20240418085725.373797-3-dharma.b%40microchip.com
patch subject: [PATCH v7 2/4] drm/bridge: add lvds controller support for sam9x7
config: arm-at91_dt_defconfig (https://download.01.org/0day-ci/archive/20240421/202404210232.jI4lxq3k-lkp@intel.com/config)
compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project 7089c359a3845323f6f30c44a47dd901f2edfe63)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240421/202404210232.jI4lxq3k-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/202404210232.jI4lxq3k-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/gpu/drm/bridge/microchip-lvds.c:17:
   In file included from include/linux/phy/phy.h:17:
   In file included from include/linux/regulator/consumer.h:35:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:21:
   In file included from include/linux/mm.h:2208:
   include/linux/vmstat.h:522:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     522 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
>> drivers/gpu/drm/bridge/microchip-lvds.c:199:6: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
     199 |         if (ret < 0) {
         |             ^~~
   drivers/gpu/drm/bridge/microchip-lvds.c:154:9: note: initialize the variable 'ret' to silence this warning
     154 |         int ret;
         |                ^
         |                 = 0
   2 warnings generated.


vim +/ret +199 drivers/gpu/drm/bridge/microchip-lvds.c

   148	
   149	static int mchp_lvds_probe(struct platform_device *pdev)
   150	{
   151		struct device *dev = &pdev->dev;
   152		struct mchp_lvds *lvds;
   153		struct device_node *port;
   154		int ret;
   155	
   156		if (!dev->of_node)
   157			return -ENODEV;
   158	
   159		lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
   160		if (!lvds)
   161			return -ENOMEM;
   162	
   163		lvds->dev = dev;
   164	
   165		lvds->regs = devm_ioremap_resource(lvds->dev,
   166				platform_get_resource(pdev, IORESOURCE_MEM, 0));
   167		if (IS_ERR(lvds->regs))
   168			return PTR_ERR(lvds->regs);
   169	
   170		lvds->pclk = devm_clk_get(lvds->dev, "pclk");
   171		if (IS_ERR(lvds->pclk))
   172			return dev_err_probe(lvds->dev, PTR_ERR(lvds->pclk),
   173					"could not get pclk_lvds\n");
   174	
   175		port = of_graph_get_remote_node(dev->of_node, 1, 0);
   176		if (!port) {
   177			dev_err(dev,
   178				"can't find port point, please init lvds panel port!\n");
   179			return -ENODEV;
   180		}
   181	
   182		lvds->panel = of_drm_find_panel(port);
   183		of_node_put(port);
   184	
   185		if (IS_ERR(lvds->panel))
   186			return -EPROBE_DEFER;
   187	
   188		lvds->panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
   189	
   190		if (IS_ERR(lvds->panel_bridge))
   191			return PTR_ERR(lvds->panel_bridge);
   192	
   193		lvds->bridge.of_node = dev->of_node;
   194		lvds->bridge.type = DRM_MODE_CONNECTOR_LVDS;
   195		lvds->bridge.funcs = &mchp_lvds_bridge_funcs;
   196	
   197		dev_set_drvdata(dev, lvds);
   198		devm_pm_runtime_enable(dev);
 > 199		if (ret < 0) {
   200			dev_err(lvds->dev, "failed to enable pm runtime: %d\n", ret);
   201			return ret;
   202		}
   203	
   204		drm_bridge_add(&lvds->bridge);
   205	
   206		return 0;
   207	}
   208	

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