From: Nathan Chancellor nathan@kernel.org
[ 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 | 2 +- drivers/soc/tegra/fuse/fuse.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c index 94b60a692b515..4388a4a5e0919 100644 --- a/drivers/soc/tegra/fuse/fuse-tegra.c +++ b/drivers/soc/tegra/fuse/fuse-tegra.c @@ -260,7 +260,7 @@ static struct platform_driver tegra_fuse_driver = { }; builtin_platform_driver(tegra_fuse_driver);
-bool __init tegra_fuse_read_spare(unsigned int spare) +u32 __init tegra_fuse_read_spare(unsigned int spare) { unsigned int offset = fuse->soc->info->spare + spare * 4;
diff --git a/drivers/soc/tegra/fuse/fuse.h b/drivers/soc/tegra/fuse/fuse.h index e057a58e20603..21887a57cf2c2 100644 --- a/drivers/soc/tegra/fuse/fuse.h +++ b/drivers/soc/tegra/fuse/fuse.h @@ -63,7 +63,7 @@ struct tegra_fuse { void tegra_init_revision(void); void tegra_init_apbmisc(void);
-bool __init tegra_fuse_read_spare(unsigned int spare); +u32 __init tegra_fuse_read_spare(unsigned int spare); u32 __init tegra_fuse_read_early(unsigned int offset);
u8 tegra_get_major_rev(void);