Re: [PATCH 1/1] phy: intel: Fix compilation error on FIELD_PREP usage

[Randy Dunlap]

On 5/26/20 1:43 AM, Dilip Kota wrote:
> FIELD_PREP expects mask variable datatype as unsigned long and constant.
> Make the mask argument in combo_phy_w32_off_mask () as unsigned long const
> datatype.
> 
> Error reported as:
> In file included from include/linux/build_bug.h:5,
> from include/linux/bitfield.h:10,
> from drivers/phy/intel/phy-intel-combo.c:8:
> drivers/phy/intel/phy-intel-combo.c: In function 'combo_phy_w32_off_mask':
> include/linux/bitfield.h:52:28: warning: comparison is always false due to limited range of data type [-Wtype-limits]
> 
> include/linux/compiler.h:350:38: error: call to '__compiletime_assert_37' declared with attribute error: FIELD_PREP: mask is not constant
> 94 |   __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");          |   ^~~~~~~~~~~~~~~~
> drivers/phy/intel/phy-intel-combo.c:137:13: note: in expansion of macro 'FIELD_PREP'
> 137 |  reg_val |= FIELD_PREP(mask, val);
> |             ^~~~~~~~~~
> 
> Fixes: ac0a95a3ea78 ("phy: intel: Add driver support for ComboPhy")
> Signed-off-by: Dilip Kota <eswara.kota@xxxxxxxxxxxxxxx>
> Reported-by: kbuild test robot <lkp@xxxxxxxxx>

also
Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

here:
https://lore.kernel.org/linux-fsdevel/9960b5aa-4a8e-15a4-6e0b-63561f760d3a@xxxxxxxxxxxxx/

but I still see build errors after applying this patch.

  CC      drivers/phy/intel/phy-intel-combo.o
In file included from ../include/linux/build_bug.h:5:0,
                 from ../include/linux/bitfield.h:10,
                 from ../drivers/phy/intel/phy-intel-combo.c:8:
../drivers/phy/intel/phy-intel-combo.c: In function âcombo_phy_w32_off_maskâ:
../include/linux/compiler.h:392:38: error: call to â__compiletime_assert_133â declared with attribute error: FIELD_PREP: mask is not constant
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
                                      ^
../include/linux/compiler.h:373:4: note: in definition of macro â__compiletime_assertâ
    prefix ## suffix();    \
    ^~~~~~
../include/linux/compiler.h:392:2: note: in expansion of macro â_compiletime_assertâ
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
  ^~~~~~~~~~~~~~~~~~~
../include/linux/build_bug.h:39:37: note: in expansion of macro âcompiletime_assertâ
 #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                     ^~~~~~~~~~~~~~~~~~
../include/linux/bitfield.h:46:3: note: in expansion of macro âBUILD_BUG_ON_MSGâ
   BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask),  \
   ^~~~~~~~~~~~~~~~
../include/linux/bitfield.h:94:3: note: in expansion of macro â__BF_FIELD_CHECKâ
   __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
   ^~~~~~~~~~~~~~~~
../drivers/phy/intel/phy-intel-combo.c:137:13: note: in expansion of macro âFIELD_PREPâ
  reg_val |= FIELD_PREP(mask, val);
             ^~~~~~~~~~
../include/linux/compiler.h:392:38: error: call to â__compiletime_assert_137â declared with attribute error: BUILD_BUG_ON failed: (((mask) + (1ULL << (__builtin_ffsll(mask) - 1))) & (((mask) + (1ULL << (__builtin_ffsll(mask) - 1))) - 1)) != 0
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
                                      ^
../include/linux/compiler.h:373:4: note: in definition of macro â__compiletime_assertâ
    prefix ## suffix();    \
    ^~~~~~
../include/linux/compiler.h:392:2: note: in expansion of macro â_compiletime_assertâ
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
  ^~~~~~~~~~~~~~~~~~~
../include/linux/build_bug.h:39:37: note: in expansion of macro âcompiletime_assertâ
 #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                     ^~~~~~~~~~~~~~~~~~
../include/linux/build_bug.h:50:2: note: in expansion of macro âBUILD_BUG_ON_MSGâ
  BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
  ^~~~~~~~~~~~~~~~
../include/linux/build_bug.h:21:2: note: in expansion of macro âBUILD_BUG_ONâ
  BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
  ^~~~~~~~~~~~
../include/linux/bitfield.h:54:3: note: in expansion of macro â__BUILD_BUG_ON_NOT_POWER_OF_2â
   __BUILD_BUG_ON_NOT_POWER_OF_2((_mask) +   \
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../include/linux/bitfield.h:94:3: note: in expansion of macro â__BF_FIELD_CHECKâ
   __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
   ^~~~~~~~~~~~~~~~
../drivers/phy/intel/phy-intel-combo.c:137:13: note: in expansion of macro âFIELD_PREPâ
  reg_val |= FIELD_PREP(mask, val);
             ^~~~~~~~~~


> ---
>  drivers/phy/intel/phy-intel-combo.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/intel/phy-intel-combo.c b/drivers/phy/intel/phy-intel-combo.c
> index c2a35be4cdfb..05b7d724ceb0 100644
> --- a/drivers/phy/intel/phy-intel-combo.c
> +++ b/drivers/phy/intel/phy-intel-combo.c
> @@ -128,7 +128,7 @@ static int intel_cbphy_pcie_refclk_cfg(struct intel_cbphy_iphy *iphy, bool set)
>  }
>  
>  static inline void combo_phy_w32_off_mask(void __iomem *base, unsigned int reg,
> -					  u32 mask, u32 val)
> +					  unsigned long const mask, u32 val)
>  {
>  	u32 reg_val;
>  
> 


-- 
~Randy