Hi Bean,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v5.7-rc6 next-20200518]
[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/Bean-Huo/Micron-SLC-NAND-filling-block/20200518-220231
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git b9bbe6ed63b2b9f2c9ee5cbd0f2c946a2723f4ce
config: m68k-allmodconfig (attached as .config)
compiler: m68k-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=m68k 

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

All errors (new ones prefixed by >>, old ones prefixed by <<):

drivers/mtd/nand/raw/nand_base.c: In function 'nand_check_is_erased_page':
>> drivers/mtd/nand/raw/nand_base.c:2611:2: error: 'max_bitflips' undeclared (first use in this function)
2611 |  max_bitflips = 0;
|  ^~~~~~~~~~~~
drivers/mtd/nand/raw/nand_base.c:2611:2: note: each undeclared identifier is reported only once for each function it appears in

vim +/max_bitflips +2611 drivers/mtd/nand/raw/nand_base.c

  2586	
  2587	/**
  2588	 * nand_check_is_erased_page - check if this page is a empty page
  2589	 * @chip: nand chip info structure
  2590	 * @page_data: data buffer containing the data in the page being checked
  2591	 * @oob: indicate if chip->oob_poi points to oob date of the page
  2592	 *
  2593	 * Returns true if this is an un-programmed page, false otherwise.
  2594	 */
  2595	int nand_check_is_erased_page(struct nand_chip *chip, u8 *page_data, bool oob)
  2596	{
  2597		struct mtd_info *mtd = nand_to_mtd(chip);
  2598		int ret, i;
  2599		u8 *databuf, *eccbuf = NULL;
  2600		struct mtd_oob_region oobregion;
  2601		int datasize, eccbytes = 0;
  2602	
  2603		databuf = page_data;
  2604		datasize = chip->ecc.size;
  2605	
  2606		if (oob) {
  2607			mtd_ooblayout_ecc(mtd, 0, &oobregion);
  2608			eccbuf = chip->oob_poi + oobregion.offset;
  2609			eccbytes = chip->ecc.bytes;
  2610		}
> 2611		max_bitflips = 0;
  2612	
  2613		for (i = 0; i < chip->ecc.steps; i++) {
  2614			ret = nand_check_erased_ecc_chunk(databuf, datasize,
  2615							  eccbuf, eccbytes,
  2616							  NULL, 0, chip->ecc.strength);
  2617			if (ret < 0)
  2618				return false;
  2619	
  2620			databuf += chip->ecc.size;
  2621			eccbuf += chip->ecc.bytes;
  2622		}
  2623	
  2624		return ret;
  2625	}
  2626	EXPORT_SYMBOL(nand_check_is_erased_page);
  2627	

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