linux-kernel - [PATCH] macintosh: windfarm: Use unsigned type for 1-bit bitfields

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Message-Id: <20230215-windfarm-wsingle-bit-bitfield-constant-conversion-v1-1-26415072e855@kernel.org>
Date:   Wed, 15 Feb 2023 10:12:12 -0700
From:   Nathan Chancellor <nathan@...nel.org>
To:     mpe@...erman.id.au, benh@...nel.crashing.org
Cc:     linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
        llvm@...ts.linux.dev, patches@...ts.linux.dev,
        Nathan Chancellor <nathan@...nel.org>
Subject: [PATCH] macintosh: windfarm: Use unsigned type for 1-bit bitfields

Clang warns:

  drivers/macintosh/windfarm_lm75_sensor.c:63:14: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
                  lm->inited = 1;
                             ^ ~

  drivers/macintosh/windfarm_smu_sensors.c:356:19: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
                  pow->fake_volts = 1;
                                  ^ ~
  drivers/macintosh/windfarm_smu_sensors.c:368:18: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
                  pow->quadratic = 1;
                                 ^ ~

There is no bug here since no code checks the actual value of these
fields, just whether or not they are zero (boolean context), but this
can be easily fixed by switching to an unsigned type.

Signed-off-by: Nathan Chancellor <nathan@...nel.org>
---
 drivers/macintosh/windfarm_lm75_sensor.c | 4 ++--
 drivers/macintosh/windfarm_smu_sensors.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/macintosh/windfarm_lm75_sensor.c b/drivers/macintosh/windfarm_lm75_sensor.c
index 24f0a444d312..9c6febce2376 100644
--- a/drivers/macintosh/windfarm_lm75_sensor.c
+++ b/drivers/macintosh/windfarm_lm75_sensor.c
@@ -33,8 +33,8 @@
 #endif
 
 struct wf_lm75_sensor {
-	int			ds1775 : 1;
-	int			inited : 1;
+	unsigned int		ds1775 : 1;
+	unsigned int		inited : 1;
 	struct i2c_client	*i2c;
 	struct wf_sensor	sens;
 };
diff --git a/drivers/macintosh/windfarm_smu_sensors.c b/drivers/macintosh/windfarm_smu_sensors.c
index 00c6fe25fcba..2bdb73b34d29 100644
--- a/drivers/macintosh/windfarm_smu_sensors.c
+++ b/drivers/macintosh/windfarm_smu_sensors.c
@@ -274,8 +274,8 @@ struct smu_cpu_power_sensor {
 	struct list_head	link;
 	struct wf_sensor	*volts;
 	struct wf_sensor	*amps;
-	int			fake_volts : 1;
-	int			quadratic : 1;
+	unsigned int		fake_volts : 1;
+	unsigned int		quadratic : 1;
 	struct wf_sensor	sens;
 };
 #define to_smu_cpu_power(c) container_of(c, struct smu_cpu_power_sensor, sens)

---
base-commit: ceaa837f96adb69c0df0397937cd74991d5d821a
change-id: 20230215-windfarm-wsingle-bit-bitfield-constant-conversion-324fed6e2342

Best regards,
-- 
Nathan Chancellor <nathan@...nel.org>