Hi Clark,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on spi/for-next]
[also build test ERROR on next-20181019]
[cannot apply to v4.19]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Clark-Wang/spi-lpspi-Add-slave-mode-support-for-imx7ulp/20181024-125200
base:   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
config: xtensa-allyesconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 8.1.0
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
        GCC_VERSION=8.1.0 make.cross ARCH=xtensa 

Note: the linux-review/Clark-Wang/spi-lpspi-Add-slave-mode-support-for-imx7ulp/20181024-125200 HEAD 37fc79ae346a636e850e4b90070c7d6e84b67b52 builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

   drivers/spi/spi-fsl-lpspi.c: In function 'fsl_lpspi_transfer_one':
>> drivers/spi/spi-fsl-lpspi.c:387:8: error: implicit declaration of function 'fsl_lpspi_txfifo_empty'; did you mean 'fsl_lpspi_set_cmd'? [-Werror=implicit-function-declaration]
     ret = fsl_lpspi_txfifo_empty(fsl_lpspi);
           ^~~~~~~~~~~~~~~~~~~~~~
           fsl_lpspi_set_cmd
   cc1: some warnings being treated as errors

vim +387 drivers/spi/spi-fsl-lpspi.c

8e2c76586 Clark Wang 2018-10-24  365  
8e2c76586 Clark Wang 2018-10-24  366  static int fsl_lpspi_transfer_one(struct spi_controller *controller,
5314987de Gao Pan    2016-11-22  367  				  struct spi_device *spi,
5314987de Gao Pan    2016-11-22  368  				  struct spi_transfer *t)
5314987de Gao Pan    2016-11-22  369  {
8e2c76586 Clark Wang 2018-10-24  370  	struct fsl_lpspi_data *fsl_lpspi =
8e2c76586 Clark Wang 2018-10-24  371  				spi_controller_get_devdata(controller);
5314987de Gao Pan    2016-11-22  372  	int ret;
5314987de Gao Pan    2016-11-22  373  
5314987de Gao Pan    2016-11-22  374  	fsl_lpspi->tx_buf = t->tx_buf;
5314987de Gao Pan    2016-11-22  375  	fsl_lpspi->rx_buf = t->rx_buf;
5314987de Gao Pan    2016-11-22  376  	fsl_lpspi->remain = t->len;
5314987de Gao Pan    2016-11-22  377  
5314987de Gao Pan    2016-11-22  378  	reinit_completion(&fsl_lpspi->xfer_done);
8e2c76586 Clark Wang 2018-10-24  379  	fsl_lpspi->slave_aborted = false;
8e2c76586 Clark Wang 2018-10-24  380  
5314987de Gao Pan    2016-11-22  381  	fsl_lpspi_write_tx_fifo(fsl_lpspi);
d2ad0a62d Gao Pan    2016-11-28  382  
8e2c76586 Clark Wang 2018-10-24  383  	ret = fsl_lpspi_wait_for_completion(controller);
8e2c76586 Clark Wang 2018-10-24  384  	if (ret)
8e2c76586 Clark Wang 2018-10-24  385  		return ret;
5314987de Gao Pan    2016-11-22  386  
5314987de Gao Pan    2016-11-22 @387  	ret = fsl_lpspi_txfifo_empty(fsl_lpspi);
d989eed20 Gao Pan    2016-12-02  388  	if (ret)
d989eed20 Gao Pan    2016-12-02  389  		return ret;
d989eed20 Gao Pan    2016-12-02  390  
d989eed20 Gao Pan    2016-12-02  391  	return 0;
5314987de Gao Pan    2016-11-22  392  }
5314987de Gao Pan    2016-11-22  393  

:::::: The code at line 387 was first introduced by commit
:::::: 5314987de5e5f5e38436ef4a69328bc472bbd63e spi: imx: add lpspi bus driver

:::::: TO: Gao Pan <pandy.gao@nxp.com>
:::::: CC: Mark Brown <broonie@kernel.org>

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