Hi Alexandru,

I love your patch! Perhaps something to improve:

[auto build test WARNING on iio/togreg]
[also build test WARNING on linux/master linus/master v5.11-rc7 next-20210125]
[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/Alexandru-Ardelean/iio-core-buffer-add-support-for-multiple-IIO-buffers-per-IIO-device/20210210-182500
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
config: h8300-randconfig-s031-20210209 (attached as .config)
compiler: h8300-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
        # apt-get install sparse
        # sparse version: v0.6.3-215-g0fb77bb6-dirty
        # https://github.com/0day-ci/linux/commit/9240fca112896274a76973066ca456b5b87eeb8c
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Alexandru-Ardelean/iio-core-buffer-add-support-for-multiple-IIO-buffers-per-IIO-device/20210210-182500
        git checkout 9240fca112896274a76973066ca456b5b87eeb8c
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=h8300 

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


"sparse warnings: (new ones prefixed by >>)"
>> drivers/iio/industrialio-buffer.c:209:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected restricted __poll_t @@     got int @@
   drivers/iio/industrialio-buffer.c:209:24: sparse:     expected restricted __poll_t
   drivers/iio/industrialio-buffer.c:209:24: sparse:     got int

vim +209 drivers/iio/industrialio-buffer.c

   200	
   201	__poll_t iio_buffer_poll_wrapper(struct file *filp,
   202					 struct poll_table_struct *wait)
   203	{
   204		struct iio_dev_buffer_pair *ib = filp->private_data;
   205		struct iio_buffer *rb = ib->buffer;
   206	
   207		/* check if buffer was opened through new API */
   208		if (test_bit(IIO_BUSY_BIT_POS, &rb->flags))
 > 209			return -EBUSY;
   210	
   211		return iio_buffer_poll(filp, wait);
   212	}
   213	

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