Hi Sebastian,

I love your patch! Yet something to improve:

[auto build test ERROR on input/next]
[also build test ERROR on v5.7-rc6 next-20200519]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Sebastian-Reichel/EXC3000-Updates/20200520-023207
base:   https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git next
config: ia64-randconfig-r023-20200519 (attached as .config)
compiler: ia64-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=ia64 

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

All error/warnings (new ones prefixed by >>, old ones prefixed by <<):

In file included from include/linux/kobject.h:20,
from include/linux/device.h:17,
from drivers/input/touchscreen/exc3000.c:11:
>> drivers/input/touchscreen/exc3000.c:252:23: error: initialization of 'ssize_t (*)(struct device *, struct device_attribute *, char *)' {aka 'long int (*)(struct device *, struct device_attribute *, char *)'} from incompatible pointer type 'int (*)(struct device *, struct device_attribute *, char *)' [-Werror=incompatible-pointer-types]
252 | static DEVICE_ATTR_RO(fw_version);
|                       ^~~~~~~~~~
include/linux/sysfs.h:117:10: note: in definition of macro '__ATTR_RO'
117 |  .show = _name##_show,               |          ^~~~~
>> drivers/input/touchscreen/exc3000.c:252:8: note: in expansion of macro 'DEVICE_ATTR_RO'
252 | static DEVICE_ATTR_RO(fw_version);
|        ^~~~~~~~~~~~~~
drivers/input/touchscreen/exc3000.c:252:23: note: (near initialization for 'dev_attr_fw_version.show')
252 | static DEVICE_ATTR_RO(fw_version);
|                       ^~~~~~~~~~
include/linux/sysfs.h:117:10: note: in definition of macro '__ATTR_RO'
117 |  .show = _name##_show,               |          ^~~~~
>> drivers/input/touchscreen/exc3000.c:252:8: note: in expansion of macro 'DEVICE_ATTR_RO'
252 | static DEVICE_ATTR_RO(fw_version);
|        ^~~~~~~~~~~~~~
cc1: some warnings being treated as errors

vim +252 drivers/input/touchscreen/exc3000.c

   222	
   223	static int fw_version_show(struct device *dev,
   224				   struct device_attribute *attr, char *buf)
   225	{
   226		struct exc3000_data *data = dev_get_drvdata(dev);
   227		static const u8 request[68] = {
   228			0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'D', 0x00
   229		};
   230		struct i2c_client *client = data->client;
   231		int err;
   232	
   233		mutex_lock(&data->query_lock);
   234	
   235		data->query_result = -ETIMEDOUT;
   236		reinit_completion(&data->wait_event);
   237	
   238		err = i2c_master_send(client, request, sizeof(request));
   239		if (err < 0) {
   240			mutex_unlock(&data->query_lock);
   241			return err;
   242		}
   243	
   244		wait_for_completion_interruptible_timeout(&data->wait_event, 1*HZ);
   245		mutex_unlock(&data->query_lock);
   246	
   247		if (data->query_result < 0)
   248			return data->query_result;
   249	
   250		return sprintf(buf, "%s\n", data->fw_version);
   251	}
 > 252	static DEVICE_ATTR_RO(fw_version);
   253	

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