soc/tegra: fuse: Fix bitwise vs. logical OR warning
authorNathan Chancellor <nathan@kernel.org>
Fri, 10 Dec 2021 16:55:29 +0000 (09:55 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 22 Dec 2021 08:32:43 +0000 (09:32 +0100)
commit12dc89ccaf2024d953235ca2defc40840c27965d
tree4ccda8e8b5f8f188199015d7a4d1d1b1eb842b3a
parent23311b92755ffa9087332d1bb8c71c0f6a10cc08
soc/tegra: fuse: Fix bitwise vs. logical OR warning

[ Upstream commit a7083763619f7485ccdade160deb81737cf2732f ]

A new warning in clang points out two instances where boolean
expressions are being used with a bitwise OR instead of logical OR:

drivers/soc/tegra/fuse/speedo-tegra20.c:72:9: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
                reg = tegra_fuse_read_spare(i) |
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
                                               ||
drivers/soc/tegra/fuse/speedo-tegra20.c:72:9: note: cast one or both operands to int to silence this warning
drivers/soc/tegra/fuse/speedo-tegra20.c:87:9: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
                reg = tegra_fuse_read_spare(i) |
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
                                               ||
drivers/soc/tegra/fuse/speedo-tegra20.c:87:9: note: cast one or both operands to int to silence this warning
2 warnings generated.

The motivation for the warning is that logical operations short circuit
while bitwise operations do not.

In this instance, tegra_fuse_read_spare() is not semantically returning
a boolean, it is returning a bit value. Use u32 for its return type so
that it can be used with either bitwise or boolean operators without any
warnings.

Fixes: 25cd5a391478 ("ARM: tegra: Add speedo-based process identification")
Link: https://github.com/ClangBuiltLinux/linux/issues/1488
Suggested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/soc/tegra/fuse/fuse-tegra.c
drivers/soc/tegra/fuse/fuse.h