[linux-next:master 5699/6849] drivers/bus/fsl-mc/fsl-mc-allocator.c:108:12: warning: variable 'mc_bus_dev' is uninitialized when used here

[linux-next:master 5699/6849] drivers/bus/fsl-mc/fsl-mc-allocator.c:108:12: warning: variable 'mc_bus_dev' is uninitialized when used here

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   bc708bbd8260ee4eb3428b0109f5f3be661fae46
commit: b3134039c5b3cf879841e3ec84c8cbf7675554ec [5699/6849] bus: fsl-mc: fsl-mc-allocator: Improve error reporting
config: arm64-randconfig-r012-20230602 (https://download.01.org/0day-ci/archive/20230602/202306021936.OktTcMAT-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 4faf3aaf28226a4e950c103a14f6fc1d1fdabb1b)
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=b3134039c5b3cf879841e3ec84c8cbf7675554ec
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout b3134039c5b3cf879841e3ec84c8cbf7675554ec
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/bus/fsl-mc/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306021936.OktTcMAT-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/bus/fsl-mc/fsl-mc-allocator.c:108:12: warning: variable 'mc_bus_dev' is uninitialized when used here [-Wuninitialized]
                   dev_err(&mc_bus_dev->dev, "resource mismatch\n");
                            ^~~~~~~~~~
   include/linux/dev_printk.h:144:44: note: expanded from macro 'dev_err'
           dev_printk_index_wrap(_dev_err, KERN_ERR, dev, dev_fmt(fmt), ##__VA_ARGS__)
                                                     ^~~
   include/linux/dev_printk.h:110:11: note: expanded from macro 'dev_printk_index_wrap'
                   _p_func(dev, fmt, ##__VA_ARGS__);                       \
                           ^~~
   drivers/bus/fsl-mc/fsl-mc-allocator.c:100:34: note: initialize the variable 'mc_bus_dev' to silence this warning
           struct fsl_mc_device *mc_bus_dev;
                                           ^
                                            = NULL
   drivers/bus/fsl-mc/fsl-mc-allocator.c:565:6: warning: variable 'free_count' set but not used [-Wunused-but-set-variable]
           int free_count = 0;
               ^
   2 warnings generated.


vim +/mc_bus_dev +108 drivers/bus/fsl-mc/fsl-mc-allocator.c

    87	
    88	/**
    89	 * fsl_mc_resource_pool_remove_device - remove an allocatable device from a
    90	 * resource pool
    91	 *
    92	 * @mc_dev: pointer to allocatable fsl-mc device
    93	 *
    94	 * It permanently removes an allocatable fsl-mc device from the resource
    95	 * pool. It's an error if the device is in use.
    96	 */
    97	static int __must_check fsl_mc_resource_pool_remove_device(struct fsl_mc_device
    98									   *mc_dev)
    99	{
   100		struct fsl_mc_device *mc_bus_dev;
   101		struct fsl_mc_bus *mc_bus;
   102		struct fsl_mc_resource_pool *res_pool;
   103		struct fsl_mc_resource *resource;
   104		int error = -EINVAL;
   105	
   106		resource = mc_dev->resource;
   107		if (!resource || resource->data != mc_dev) {
 > 108			dev_err(&mc_bus_dev->dev, "resource mismatch\n");
   109			goto out;
   110		}
   111	
   112		mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
   113		mc_bus = to_fsl_mc_bus(mc_bus_dev);
   114		res_pool = resource->parent_pool;
   115		if (res_pool != &mc_bus->resource_pools[resource->type]) {
   116			dev_err(&mc_bus_dev->dev, "pool mismatch\n");
   117			goto out;
   118		}
   119	
   120		mutex_lock(&res_pool->mutex);
   121	
   122		if (res_pool->max_count <= 0) {
   123			dev_err(&mc_bus_dev->dev, "max_count underflow\n");
   124			goto out_unlock;
   125		}
   126		if (res_pool->free_count <= 0 ||
   127		    res_pool->free_count > res_pool->max_count) {
   128			dev_err(&mc_bus_dev->dev, "free_count mismatch\n");
   129			goto out_unlock;
   130		}
   131	
   132		/*
   133		 * If the device is currently allocated, its resource is not
   134		 * in the free list and thus, the device cannot be removed.
   135		 */
   136		if (list_empty(&resource->node)) {
   137			error = -EBUSY;
   138			dev_err(&mc_bus_dev->dev,
   139				"Device %s cannot be removed from resource pool\n",
   140				dev_name(&mc_dev->dev));
   141			goto out_unlock;
   142		}
   143	
   144		list_del_init(&resource->node);
   145		res_pool->free_count--;
   146		res_pool->max_count--;
   147	
   148		devm_kfree(&mc_bus_dev->dev, resource);
   149		mc_dev->resource = NULL;
   150		error = 0;
   151	out_unlock:
   152		mutex_unlock(&res_pool->mutex);
   153	out:
   154		return error;
   155	}
   156	

-- 
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https://github.com/intel/lkp-tests/wiki