[PATCH 4.14 20/45] soc/tegra: fuse: Fix bitwise vs. logical OR warning

Greg Kroah-Hartman
2021-12-20T14:40:14Z

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 37bde5c8268d1..a623e498a97bc 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -178,7 +178,7 @@ 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 10c2076d5089a..f368bd5373088 100644
--- a/drivers/soc/tegra/fuse/fuse.h
+++ b/drivers/soc/tegra/fuse/fuse.h
@@ -62,7 +62,7 @@ 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);

#ifdef CONFIG_ARCH_TEGRA_2x_SOC
--
2.33.0