Re: [PATCH v5 4/4] device property: Constify fwnode APIs that uses fwnode_get_next_parent()

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

Hi Andy,

I love your patch! Perhaps something to improve:

[auto build test WARNING on driver-core/driver-core-testing]
[also build test WARNING on rafael-pm/linux-next linus/master linux/master v5.18-rc1 next-20220406]
[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/intel-lab-lkp/linux/commits/Andy-Shevchenko/device-property-Allow-error-pointer-to-be-passed-to-fwnode-APIs/20220407-002511
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git 3123109284176b1532874591f7c81f3837bbdc17
config: powerpc-allnoconfig (https://download.01.org/0day-ci/archive/20220407/202204070123.UdpbjnDH-lkp@intel.com/config)
compiler: powerpc-linux-gcc (GCC) 11.2.0
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
        # https://github.com/intel-lab-lkp/linux/commit/d9d353ada8d8c3b1b7f3965ad7fe191bd7dea930
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Andy-Shevchenko/device-property-Allow-error-pointer-to-be-passed-to-fwnode-APIs/20220407-002511
        git checkout d9d353ada8d8c3b1b7f3965ad7fe191bd7dea930
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash drivers/base/

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/base/property.c: In function 'fwnode_get_nth_parent':
>> drivers/base/property.c:647:42: warning: passing argument 1 of 'fwnode_handle_get' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
     647 |                 return fwnode_handle_get(fwnode);
         |                                          ^~~~~~
   In file included from include/linux/of.h:22,
                    from include/linux/irqdomain.h:35,
                    from include/linux/acpi.h:13,
                    from drivers/base/property.c:10:
   include/linux/property.h:123:63: note: expected 'struct fwnode_handle *' but argument is of type 'const struct fwnode_handle *'
     123 | struct fwnode_handle *fwnode_handle_get(struct fwnode_handle *fwnode);
         |                                         ~~~~~~~~~~~~~~~~~~~~~~^~~~~~


vim +647 drivers/base/property.c

87e5e95db31a27 Sakari Ailus    2019-10-03  629  
87e5e95db31a27 Sakari Ailus    2019-10-03  630  /**
87e5e95db31a27 Sakari Ailus    2019-10-03  631   * fwnode_get_nth_parent - Return an nth parent of a node
87e5e95db31a27 Sakari Ailus    2019-10-03  632   * @fwnode: The node the parent of which is requested
87e5e95db31a27 Sakari Ailus    2019-10-03  633   * @depth: Distance of the parent from the node
87e5e95db31a27 Sakari Ailus    2019-10-03  634   *
87e5e95db31a27 Sakari Ailus    2019-10-03  635   * Returns the nth parent of a node. If there is no parent at the requested
87e5e95db31a27 Sakari Ailus    2019-10-03  636   * @depth, %NULL is returned. If @depth is 0, the functionality is equivalent to
87e5e95db31a27 Sakari Ailus    2019-10-03  637   * fwnode_handle_get(). For @depth == 1, it is fwnode_get_parent() and so on.
87e5e95db31a27 Sakari Ailus    2019-10-03  638   *
87e5e95db31a27 Sakari Ailus    2019-10-03  639   * The caller is responsible for calling fwnode_handle_put() for the returned
87e5e95db31a27 Sakari Ailus    2019-10-03  640   * node.
87e5e95db31a27 Sakari Ailus    2019-10-03  641   */
d9d353ada8d8c3 Andy Shevchenko 2022-04-06  642  struct fwnode_handle *fwnode_get_nth_parent(const struct fwnode_handle *fwnode, unsigned int depth)
87e5e95db31a27 Sakari Ailus    2019-10-03  643  {
040f806ecab6cd Andy Shevchenko 2022-04-06  644  	struct fwnode_handle *parent;
87e5e95db31a27 Sakari Ailus    2019-10-03  645  
040f806ecab6cd Andy Shevchenko 2022-04-06  646  	if (depth == 0)
040f806ecab6cd Andy Shevchenko 2022-04-06 @647  		return fwnode_handle_get(fwnode);
87e5e95db31a27 Sakari Ailus    2019-10-03  648  
040f806ecab6cd Andy Shevchenko 2022-04-06  649  	fwnode_for_each_parent_node(fwnode, parent) {
040f806ecab6cd Andy Shevchenko 2022-04-06  650  		if (--depth == 0)
040f806ecab6cd Andy Shevchenko 2022-04-06  651  			return parent;
040f806ecab6cd Andy Shevchenko 2022-04-06  652  	}
040f806ecab6cd Andy Shevchenko 2022-04-06  653  	return NULL;
87e5e95db31a27 Sakari Ailus    2019-10-03  654  }
87e5e95db31a27 Sakari Ailus    2019-10-03  655  EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
87e5e95db31a27 Sakari Ailus    2019-10-03  656  

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