include/linux/compiler_types.h:597:38: error: call to '__compiletime_assert_495' declared with attribute error: FIELD_PREP: value too large for the field

[kernel test robot <lkp@intel.com>]

Hi Marek,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   a66191c590b3b58eaff05d2277971f854772bd5b
commit: 4f716a1db661cfb31502a0a6d7e62c06daf2e603 drm/rcar-du: dsi: Convert register bitfields to GENMASK() macro
date:   3 months ago
config: arc-randconfig-r053-20260123 (https://download.01.org/0day-ci/archive/20260123/202601230809.FBjF6OrH-lkp@intel.com/config)
compiler: arc-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260123/202601230809.FBjF6OrH-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601230809.FBjF6OrH-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from <command-line>:
   drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi.c: In function 'rcar_mipi_dsi_startup.isra.6':
>> include/linux/compiler_types.h:597:38: error: call to '__compiletime_assert_495' declared with attribute error: FIELD_PREP: value too large for the field
     _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
                                         ^
   include/linux/compiler_types.h:578:4: note: in definition of macro '__compiletime_assert'
       prefix ## suffix();    \
       ^~~~~~
   include/linux/compiler_types.h:597:2: note: in expansion of macro '_compiletime_assert'
     _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
     ^~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
    #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                        ^~~~~~~~~~~~~~~~~~
   include/linux/bitfield.h:68:3: note: in expansion of macro 'BUILD_BUG_ON_MSG'
      BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?  \
      ^~~~~~~~~~~~~~~~
   include/linux/bitfield.h:115:3: note: in expansion of macro '__BF_FIELD_CHECK'
      __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
      ^~~~~~~~~~~~~~~~
   drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi_regs.h:259:29: note: in expansion of macro 'FIELD_PREP'
    #define VCLKSET_DIV_V4H(n)  FIELD_PREP(VCLKSET_DIV_V4H_MASK, (n))
                                ^~~~~~~~~~
   drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi.c:660:14: note: in expansion of macro 'VCLKSET_DIV_V4H'
      vclkset |= VCLKSET_DIV_V4H(__ffs(setup_info.vclk_divider) - 1);
                 ^~~~~~~~~~~~~~~


vim +/__compiletime_assert_495 +597 include/linux/compiler_types.h

eb5c2d4b45e3d2d Will Deacon 2020-07-21  583  
eb5c2d4b45e3d2d Will Deacon 2020-07-21  584  #define _compiletime_assert(condition, msg, prefix, suffix) \
eb5c2d4b45e3d2d Will Deacon 2020-07-21  585  	__compiletime_assert(condition, msg, prefix, suffix)
eb5c2d4b45e3d2d Will Deacon 2020-07-21  586  
eb5c2d4b45e3d2d Will Deacon 2020-07-21  587  /**
eb5c2d4b45e3d2d Will Deacon 2020-07-21  588   * compiletime_assert - break build and emit msg if condition is false
eb5c2d4b45e3d2d Will Deacon 2020-07-21  589   * @condition: a compile-time constant condition to check
eb5c2d4b45e3d2d Will Deacon 2020-07-21  590   * @msg:       a message to emit if condition is false
eb5c2d4b45e3d2d Will Deacon 2020-07-21  591   *
eb5c2d4b45e3d2d Will Deacon 2020-07-21  592   * In tradition of POSIX assert, this macro will break the build if the
eb5c2d4b45e3d2d Will Deacon 2020-07-21  593   * supplied condition is *false*, emitting the supplied error message if the
eb5c2d4b45e3d2d Will Deacon 2020-07-21  594   * compiler has support to do so.
eb5c2d4b45e3d2d Will Deacon 2020-07-21  595   */
eb5c2d4b45e3d2d Will Deacon 2020-07-21  596  #define compiletime_assert(condition, msg) \
eb5c2d4b45e3d2d Will Deacon 2020-07-21 @597  	_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
eb5c2d4b45e3d2d Will Deacon 2020-07-21  598  

:::::: The code at line 597 was first introduced by commit
:::::: eb5c2d4b45e3d2d5d052ea6b8f1463976b1020d5 compiler.h: Move compiletime_assert() macros into compiler_types.h

:::::: TO: Will Deacon <will@kernel.org>
:::::: CC: Will Deacon <will@kernel.org>

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