[dinguyen:v5.10_socfpga_reset_fix 1/1] drivers/reset/reset-socfpga.c:35:6: warning: variable 'size' is used uninitialized whenever 'if' condition is true

[dinguyen:v5.10_socfpga_reset_fix 1/1] drivers/reset/reset-socfpga.c:35:6: warning: variable 'size' is used uninitialized whenever 'if' condition is true

[kernel test robot]

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux.git v5.10_socfpga_reset_fix
head:   2e7fffa64d1ec2ecb8bc368ec37e5ae2ac8cc6a1
commit: 2e7fffa64d1ec2ecb8bc368ec37e5ae2ac8cc6a1 [1/1] reset: socfpga: add error handling and release mem-region
config: x86_64-randconfig-a006-20201026 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 50dfa19cc799ae7cddd39a95dbfce675a12672ad)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux.git/commit/?id=2e7fffa64d1ec2ecb8bc368ec37e5ae2ac8cc6a1
        git remote add dinguyen https://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux.git
        git fetch --no-tags dinguyen v5.10_socfpga_reset_fix
        git checkout 2e7fffa64d1ec2ecb8bc368ec37e5ae2ac8cc6a1
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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

All warnings (new ones prefixed by >>):

>> drivers/reset/reset-socfpga.c:35:6: warning: variable 'size' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
           if (ret)
               ^~~
   drivers/reset/reset-socfpga.c:69:32: note: uninitialized use occurs here
           release_mem_region(res.start, size);
                                         ^~~~
   include/linux/ioport.h:249:81: note: expanded from macro 'release_mem_region'
   #define release_mem_region(start,n)     __release_region(&iomem_resource, (start), (n))
                                                                                       ^
   drivers/reset/reset-socfpga.c:35:2: note: remove the 'if' if its condition is always false
           if (ret)
           ^~~~~~~~
   drivers/reset/reset-socfpga.c:26:22: note: initialize the variable 'size' to silence this warning
           resource_size_t size;
                               ^
                                = 0
   1 warning generated.

vim +35 drivers/reset/reset-socfpga.c

b3ca9888f35fa6 Dinh Nguyen 2018-11-13  21  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  22  static int a10_reset_init(struct device_node *np)
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  23  {
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  24  	struct reset_simple_data *data;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  25  	struct resource res;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  26  	resource_size_t size;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  27  	int ret;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  28  	u32 reg_offset = 0x10;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  29  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  30  	data = kzalloc(sizeof(*data), GFP_KERNEL);
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  31  	if (!data)
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  32  		return -ENOMEM;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  33  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  34  	ret = of_address_to_resource(np, 0, &res);
b3ca9888f35fa6 Dinh Nguyen 2018-11-13 @35  	if (ret)
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  36  		goto err_alloc;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  37  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  38  	size = resource_size(&res);
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  39  	if (!request_mem_region(res.start, size, np->name)) {
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  40  		ret = -EBUSY;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  41  		goto err_alloc;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  42  	}
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  43  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  44  	data->membase = ioremap(res.start, size);
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  45  	if (!data->membase) {
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  46  		ret = -ENOMEM;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  47  		goto err_alloc;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  48  	}
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  49  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  50  	if (of_property_read_u32(np, "altr,modrst-offset", &reg_offset))
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  51  		pr_warn("missing altr,modrst-offset property, assuming 0x10\n");
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  52  	data->membase += reg_offset;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  53  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  54  	spin_lock_init(&data->lock);
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  55  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  56  	data->rcdev.owner = THIS_MODULE;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  57  	data->rcdev.nr_resets = SOCFPGA_NR_BANKS * 32;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  58  	data->rcdev.ops = &reset_simple_ops;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  59  	data->rcdev.of_node = np;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  60  	data->status_active_low = true;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  61  
2e7fffa64d1ec2 Dinh Nguyen 2020-10-27  62  	ret = reset_controller_register(&data->rcdev);
2e7fffa64d1ec2 Dinh Nguyen 2020-10-27  63  	if (ret)
2e7fffa64d1ec2 Dinh Nguyen 2020-10-27  64  		pr_err("unable to register device\n");
2e7fffa64d1ec2 Dinh Nguyen 2020-10-27  65  
2e7fffa64d1ec2 Dinh Nguyen 2020-10-27  66  	return 0;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  67  
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  68  err_alloc:
2e7fffa64d1ec2 Dinh Nguyen 2020-10-27  69  	release_mem_region(res.start, size);
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  70  	kfree(data);
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  71  	return ret;
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  72  };
b3ca9888f35fa6 Dinh Nguyen 2018-11-13  73  

:::::: The code at line 35 was first introduced by commit
:::::: b3ca9888f35fa6919569cf27c929dc0ac49e9716 reset: socfpga: add an early reset driver for SoCFPGA

:::::: TO: Dinh Nguyen <dinguyen@kernel.org>
:::::: CC: Philipp Zabel <p.zabel@pengutronix.de>

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

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