Re: [mtd:spi-mem-ecc 29/29] drivers/spi/spi-mxic.c:688: undefined reference to `nand_ecc_unregister_on_host_hw_engine'

[Miquel Raynal <miquel.raynal@bootlin.com>]

lkp@intel.com wrote on Fri, 28 Jan 2022 21:01:33 +0800:

> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git spi-mem-ecc
> head:   493b08141c0086ddb2126179cca7a8a7936b3582
> commit: 493b08141c0086ddb2126179cca7a8a7936b3582 [29/29] spi: mxic: Add support for pipelined ECC operations
> config: i386-randconfig-a014-20210930 (https://download.01.org/0day-ci/archive/20220128/202201282024.dNzYfD56-lkp@intel.com/config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
>         # https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git/commit/?id=493b08141c0086ddb2126179cca7a8a7936b3582
>         git remote add mtd https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git
>         git fetch --no-tags mtd spi-mem-ecc
>         git checkout 493b08141c0086ddb2126179cca7a8a7936b3582
>         # save the config file to linux build tree
>         mkdir build_dir
>         make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
>    ld: drivers/spi/spi-mxic.o: in function `mxic_spi_mem_ecc_remove':
> >> drivers/spi/spi-mxic.c:688: undefined reference to `nand_ecc_unregister_on_host_hw_engine'  

Today I learned that unlike "depends on", "select" does not enforce any
type (y or m), which can lead to the following situation:

SPI_MXIC=y expects the NAND symbols to be built statically
SPI_MXIC depends on MTD_NAND_ECC
MTD_NAND_ECC selects MTD_NAND_CORE
In this case MTD_NAND_CORE=m is "valid" but will trigger link errors
such as the one below.

The problem does not directly come from that patchset but more on
the way dependencies are described under drivers/mtd/nand/. I will fix
this in another patch and apply it right before merging this series on
top of the spi-mem-ecc branch to avoid any further reports.

> 
> 
> vim +688 drivers/spi/spi-mxic.c
> 
>    683	
>    684	static void mxic_spi_mem_ecc_remove(struct mxic_spi *mxic)
>    685	{
>    686		if (mxic->ecc.pipelined_engine) {
>    687			mxic_ecc_put_pipelined_engine(mxic->ecc.pipelined_engine);
>  > 688			nand_ecc_unregister_on_host_hw_engine(mxic->ecc.pipelined_engine);  
>    689		}
>    690	}
>    691	
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org


Thanks,
Miquèl