Hi Mike,

I love your patch! Perhaps something to improve:

[auto build test WARNING on lwn/docs-next]
[also build test WARNING on linus/master v5.12-rc3 next-20210316]
[cannot apply to soc/for-next]
[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/Mike-Leach/CoreSight-configuration-management-ETM-strobing/20210317-021436
base:   git://git.lwn.net/linux-2.6 docs-next
config: arm-randconfig-r035-20210316 (attached as .config)
compiler: arm-linux-gnueabi-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/76d2cecb5af2a820d6910c10996ed11222799ce8
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Mike-Leach/CoreSight-configuration-management-ETM-strobing/20210317-021436
        git checkout 76d2cecb5af2a820d6910c10996ed11222799ce8
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All warnings (new ones prefixed by >>):

quoted

drivers/hwtracing/coresight/coresight-syscfg.c:132:6: warning: no previous prototype for 'cscfg_dev_release' [-Wmissing-prototypes]

     132 | void cscfg_dev_release(struct device *dev)
         |      ^~~~~~~~~~~~~~~~~

quoted

drivers/hwtracing/coresight/coresight-syscfg.c:139:5: warning: no previous prototype for 'cscfg_create_device' [-Wmissing-prototypes]

     139 | int cscfg_create_device(void)
         |     ^~~~~~~~~~~~~~~~~~~

quoted

drivers/hwtracing/coresight/coresight-syscfg.c:168:6: warning: no previous prototype for 'cscfg_clear_device' [-Wmissing-prototypes]

     168 | void cscfg_clear_device(void)
         |      ^~~~~~~~~~~~~~~~~~


vim +/cscfg_dev_release +132 drivers/hwtracing/coresight/coresight-syscfg.c

   130	
   131	/* Must have a release function or the kernel will complain on module unload */
 > 132	void cscfg_dev_release(struct device *dev)
   133	{
   134		kfree(cscfg_mgr);
   135		cscfg_mgr = NULL;
   136	}
   137	
   138	/* a device is needed to "own" some kernel elements such as sysfs entries.  */
 > 139	int cscfg_create_device(void)
   140	{
   141		struct device *dev;
   142		int err = -ENOMEM;
   143	
   144		mutex_lock(&cscfg_mutex);
   145		if (cscfg_mgr) {
   146			err = -EINVAL;
   147			goto create_dev_exit_unlock;
   148		}
   149	
   150		cscfg_mgr = kzalloc(sizeof(struct cscfg_manager), GFP_KERNEL);
   151		if (!cscfg_mgr)
   152			goto create_dev_exit_unlock;
   153	
   154		/* setup the device */
   155		dev = cscfg_device();
   156		dev->release = cscfg_dev_release;
   157		dev->init_name = "cs_system_cfg";
   158	
   159		err = device_register(dev);
   160		if (err)
   161			cscfg_dev_release(dev);
   162	
   163	create_dev_exit_unlock:
   164		mutex_unlock(&cscfg_mutex);
   165		return err;
   166	}
   167	
 > 168	void cscfg_clear_device(void)
   169	{
   170		mutex_lock(&cscfg_mutex);
   171		device_unregister(cscfg_device());
   172		mutex_unlock(&cscfg_mutex);
   173	}
   174	

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