[PATCH 5.10 49/99] soc/tegra: fuse: Fix bitwise vs. logical OR warning - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	"Michał Mirosław" <mirq-linux@rere.qmqm.pl>,
	"Nathan Chancellor" <nathan@kernel.org>,
	"Nick Desaulniers" <ndesaulniers@google.com>,
	"Thierry Reding" <treding@nvidia.com>,
	"Sasha Levin" <sashal@kernel.org>
Subject: [PATCH 5.10 49/99] soc/tegra: fuse: Fix bitwise vs. logical OR warning
Date: Mon, 20 Dec 2021 15:34:22 +0100	[thread overview]
Message-ID: <20211220143031.028039902@linuxfoundation.org> (raw)
In-Reply-To: <20211220143029.352940568@linuxfoundation.org>

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);
-- 
2.33.0



