Re: [PATCH v1 4/5] driver core: Handle cycles in device links created by fw_devlink

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

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Hi Saravana,

I love your patch! Perhaps something to improve:

[auto build test WARNING on driver-core/driver-core-testing]
[also build test WARNING on linus/master next-20201217]
[cannot apply to linux/master v5.10]
[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/Saravana-Kannan/Enable-fw_devlink-on-by-default/20201218-112111
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git accefff5b547a9a1d959c7e76ad539bf2480e78b
config: mips-randconfig-r016-20201217 (attached as .config)
compiler: mips64-linux-gcc (GCC) 9.3.0
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/0day-ci/linux/commit/7bdc87ea0400318d827410f454ec7e5fbaf470c3
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Saravana-Kannan/Enable-fw_devlink-on-by-default/20201218-112111
        git checkout 7bdc87ea0400318d827410f454ec7e5fbaf470c3
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips 

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/core.c:1522:5: warning: no previous prototype for 'fw_devlink_relax_cycle' [-Wmissing-prototypes]
    1522 | int fw_devlink_relax_cycle(struct device *con, void *sup)
         |     ^~~~~~~~~~~~~~~~~~~~~~


vim +/fw_devlink_relax_cycle +1522 drivers/base/core.c

  1507	
  1508	/**
  1509	 * fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links
  1510	 * @con: Device to check dependencies for.
  1511	 * @sup: Device to check against.
  1512	 *
  1513	 * Check if @sup depends on @con or any device dependent on it (its child or
  1514	 * its consumer etc).  When such a cyclic dependency is found, convert all
  1515	 * device links created solely by fw_devlink into SYNC_STATE_ONLY device links.
  1516	 * This is the equivalent of doing fw_devlink=permissive just between the
  1517	 * devices in the cycle. We need to do this because, at this point, fw_devlink
  1518	 * can't tell which of these dependencies is not a real dependency.
  1519	 *
  1520	 * Return 1 if a cycle is found. Otherwise, return 0.
  1521	 */
> 1522	int fw_devlink_relax_cycle(struct device *con, void *sup)
  1523	{
  1524		struct device_link *link;
  1525		int ret;
  1526	
  1527		if (con == sup)
  1528			return 1;
  1529	
  1530		ret = device_for_each_child(con, sup, fw_devlink_relax_cycle);
  1531		if (ret)
  1532			return ret;
  1533	
  1534		list_for_each_entry(link, &con->links.consumers, s_node) {
  1535			if ((link->flags & ~DL_FLAG_INFERRED) ==
  1536			    (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
  1537				continue;
  1538	
  1539			if (!fw_devlink_relax_cycle(link->consumer, sup))
  1540				continue;
  1541	
  1542			ret = 1;
  1543	
  1544			if (!(link->flags & DL_FLAG_INFERRED))
  1545				continue;
  1546	
  1547			pm_runtime_drop_link(link);
  1548			link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
  1549			dev_dbg(link->consumer, "Relaxing link with %s\n",
  1550				dev_name(link->supplier));
  1551		}
  1552		return ret;
  1553	}
  1554	

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

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