Hi Ulf,

I love your patch! Perhaps something to improve:

[auto build test WARNING on pm/linux-next]
[also build test WARNING on v5.13 next-20210709]
[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/Ulf-Hansson/PM-domains-Don-t-attach-a-device-to-genpd-that-corresponds-to-a-provider/20210709-205736
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: arm-randconfig-r005-20210709 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 8d69635ed9ecf36fd0ca85906bfde17949671cbe)
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 arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/0day-ci/linux/commit/5f3ae7877b4b3a9c2c4d96c2106c41b16b981958
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Ulf-Hansson/PM-domains-Don-t-attach-a-device-to-genpd-that-corresponds-to-a-provider/20210709-205736
        git checkout 5f3ae7877b4b3a9c2c4d96c2106c41b16b981958
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm 

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/power/domain.c:2704:10: warning: incompatible pointer to integer conversion returning 'void *' from a function with result type 'int' [-Wint-conversion]
                   return NULL;
                          ^~~~
   include/linux/stddef.h:8:14: note: expanded from macro 'NULL'
   #define NULL ((void *)0)
                ^~~~~~~~~~~
   1 warning generated.


vim +2704 drivers/base/power/domain.c

  2683	
  2684	/**
  2685	 * genpd_dev_pm_attach - Attach a device to its PM domain using DT.
  2686	 * @dev: Device to attach.
  2687	 *
  2688	 * Parse device's OF node to find a PM domain specifier. If such is found,
  2689	 * attaches the device to retrieved pm_domain ops.
  2690	 *
  2691	 * Returns 1 on successfully attached PM domain, 0 when the device don't need a
  2692	 * PM domain or when multiple power-domains exists for it, else a negative error
  2693	 * code. Note that if a power-domain exists for the device, but it cannot be
  2694	 * found or turned on, then return -EPROBE_DEFER to ensure that the device is
  2695	 * not probed and to re-try again later.
  2696	 */
  2697	int genpd_dev_pm_attach(struct device *dev)
  2698	{
  2699		if (!dev->of_node)
  2700			return 0;
  2701	
  2702		/* Don't try to attach a genpd provider. */
  2703		if (of_find_property(dev->of_node, "#power-domain-cells", NULL))
> 2704			return NULL;
  2705	
  2706		/*
  2707		 * Devices with multiple PM domains must be attached separately, as we
  2708		 * can only attach one PM domain per device.
  2709		 */
  2710		if (of_count_phandle_with_args(dev->of_node, "power-domains",
  2711					       "#power-domain-cells") != 1)
  2712			return 0;
  2713	
  2714		return __genpd_dev_pm_attach(dev, dev, 0, true);
  2715	}
  2716	EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
  2717	

---
0-DAY CI Kernel Test Service, Intel Corporation
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