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5c667d5a5a
When building with clang + W=1, there is a warning around an internal
comparison check within the FIELD_PREP() macro, due to a 32-bit variable
comparison against ~0ull:
drivers/clk/clk-sp7021.c:316:8: error: result of comparison of constant 18446744073709551615 with expression of type 'typeof (_Generic((_m), ...' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
r0 |= HWM_FIELD_PREP(MASK_SEL_FRA, clk->p[SEL_FRA]);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/clk/clk-sp7021.c:45:15: note: expanded from macro 'HWM_FIELD_PREP'
(_m << 16) | FIELD_PREP(_m, value); \
^~~~~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:114:3: note: expanded from macro 'FIELD_PREP'
__BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:71:53: note: expanded from macro '__BF_FIELD_CHECK'
BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) > \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
include/linux/compiler_types.h:397:22: note: expanded from macro 'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler_types.h:385:23: note: expanded from macro '_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler_types.h:377:9: note: expanded from macro '__compiletime_assert'
if (!(condition)) \
^~~~~~~~~
This is expected given the types of the input. Increase the size of the
temporary variable in HWM_FIELD_PREP() to eliminate the warning, which
follows the logic of commit cfd6fb45cf ("crypto: ccree - avoid
out-of-range warnings from clang") for the same reasons.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230501-sp7021-field_prep-warning-v1-1-5b36d71feefe@kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/202303221947.pXP2v4xJ-lkp@intel.com/
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.