Hi Chris,

I love your patch! Perhaps something to improve:

[auto build test WARNING on jeyu/modules-next]
[also build test WARNING on linux/master soc/for-next openrisc/for-next powerpc/next asm-generic/master driver-core/driver-core-testing linus/master v5.13-rc6 next-20210616]
[cannot apply to uml/linux-next tip/x86/core]
[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/Chris-Down/printk-Userspace-format-indexing-support/20210617-101450
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux.git modules-next
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/819166a91ddffdbf04d0b4e6905a5ab3b568194f
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Chris-Down/printk-Userspace-format-indexing-support/20210617-101450
        git checkout 819166a91ddffdbf04d0b4e6905a5ab3b568194f
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=sh 

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

All warnings (new ones prefixed by >>):

   kernel/printk/index.c: In function 'pi_show':
   kernel/printk/index.c:72:2: error: implicit declaration of function 'seq_escape_str'; did you mean 'seq_escape'? [-Werror=implicit-function-declaration]
      72 |  seq_escape_str(s, src, ESCAPE_ANY | ESCAPE_NAP | ESCAPE_APPEND, "\"\\")
         |  ^~~~~~~~~~~~~~
   kernel/printk/index.c:110:3: note: in expansion of macro 'seq_escape_printf_format'
     110 |   seq_escape_printf_format(s, entry->subsys_fmt_prefix);
         |   ^~~~~~~~~~~~~~~~~~~~~~~~
   kernel/printk/index.c:72:38: error: 'ESCAPE_NAP' undeclared (first use in this function); did you mean 'ESCAPE_NP'?
      72 |  seq_escape_str(s, src, ESCAPE_ANY | ESCAPE_NAP | ESCAPE_APPEND, "\"\\")
         |                                      ^~~~~~~~~~
   kernel/printk/index.c:110:3: note: in expansion of macro 'seq_escape_printf_format'
     110 |   seq_escape_printf_format(s, entry->subsys_fmt_prefix);
         |   ^~~~~~~~~~~~~~~~~~~~~~~~
   kernel/printk/index.c:72:38: note: each undeclared identifier is reported only once for each function it appears in
      72 |  seq_escape_str(s, src, ESCAPE_ANY | ESCAPE_NAP | ESCAPE_APPEND, "\"\\")
         |                                      ^~~~~~~~~~
   kernel/printk/index.c:110:3: note: in expansion of macro 'seq_escape_printf_format'
     110 |   seq_escape_printf_format(s, entry->subsys_fmt_prefix);
         |   ^~~~~~~~~~~~~~~~~~~~~~~~
   kernel/printk/index.c:72:51: error: 'ESCAPE_APPEND' undeclared (first use in this function); did you mean 'ESCAPE_ANY'?
      72 |  seq_escape_str(s, src, ESCAPE_ANY | ESCAPE_NAP | ESCAPE_APPEND, "\"\\")
         |                                                   ^~~~~~~~~~~~~
   kernel/printk/index.c:110:3: note: in expansion of macro 'seq_escape_printf_format'
     110 |   seq_escape_printf_format(s, entry->subsys_fmt_prefix);
         |   ^~~~~~~~~~~~~~~~~~~~~~~~
   kernel/printk/index.c: At top level:
>> kernel/printk/index.c:140:6: warning: no previous prototype for 'pi_create_file' [-Wmissing-prototypes]
     140 | void pi_create_file(struct module *mod)
         |      ^~~~~~~~~~~~~~
>> kernel/printk/index.c:146:6: warning: no previous prototype for 'pi_remove_file' [-Wmissing-prototypes]
     146 | void pi_remove_file(struct module *mod)
         |      ^~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_PDC
   Depends on SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && HAS_DMA
   Selected by
   - SND_ATMEL_SOC_SSC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC
   - SND_ATMEL_SOC_SSC_PDC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && ATMEL_SSC


vim +/pi_create_file +140 kernel/printk/index.c

   139	
 > 140	void pi_create_file(struct module *mod)
   141	{
   142		debugfs_create_file(pi_get_module_name(mod), 0444, dfs_index,
   143					       mod, &dfs_index_fops);
   144	}
   145	
 > 146	void pi_remove_file(struct module *mod)
   147	{
   148		debugfs_remove(debugfs_lookup(pi_get_module_name(mod), dfs_index));
   149	}
   150	

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