| Message ID | 20200603000753.391-1-Sergey.Semin@baikalelectronics.ru (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] hwmon: bt1-pvt: Define Temp- and Volt-to-N poly as maybe-unused | expand |
On Wed, Jun 03, 2020 at 03:07:53AM +0300, Serge Semin wrote: > Clang-based kernel building with W=1 warns that some static const > variables are unused: > > drivers/hwmon/bt1-pvt.c:67:30: warning: unused variable 'poly_temp_to_N' [-Wunused-const-variable] > static const struct pvt_poly poly_temp_to_N = { > ^ > drivers/hwmon/bt1-pvt.c:99:30: warning: unused variable 'poly_volt_to_N' [-Wunused-const-variable] > static const struct pvt_poly poly_volt_to_N = { > ^ > > Indeed these polynomials are utilized only when the PVT sensor alarms are > enabled. In that case they are used to convert the temperature and > voltage alarm limits from normal quantities (Volts and degree Celsius) to > the sensor data representation N = [0, 1023]. Otherwise when alarms are > disabled the driver only does the detected data conversion to the human > readable form and doesn't need that polynomials defined. So let's mark the > Temp-to-N and Volt-to-N polynomials with __maybe_unused attribute. > > Note gcc with W=1 doesn't notice the problem. > > Fixes: 87976ce2825d ("hwmon: Add Baikal-T1 PVT sensor driver") > Reported-by: kbuild test robot <lkp@intel.com> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> > Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Applied. Thanks, Guenter > --- > > Link: https://lore.kernel.org/linux-hwmon/20200602091219.24404-1-Sergey.Semin@baikalelectronics.ru > Changelog v2: > - Repalce if-defs with __maybe_unused attribute. > --- > drivers/hwmon/bt1-pvt.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwmon/bt1-pvt.c b/drivers/hwmon/bt1-pvt.c > index 1a9772fb1f73..8709b3f54086 100644 > --- a/drivers/hwmon/bt1-pvt.c > +++ b/drivers/hwmon/bt1-pvt.c > @@ -64,7 +64,7 @@ static const struct pvt_sensor_info pvt_info[] = { > * 48380, > * where T = [-48380, 147438] mC and N = [0, 1023]. > */ > -static const struct pvt_poly poly_temp_to_N = { > +static const struct pvt_poly __maybe_unused poly_temp_to_N = { > .total_divider = 10000, > .terms = { > {4, 18322, 10000, 10000}, > @@ -96,7 +96,7 @@ static const struct pvt_poly poly_N_to_temp = { > * N = (18658e-3*V - 11572) / 10, > * V = N * 10^5 / 18658 + 11572 * 10^4 / 18658. > */ > -static const struct pvt_poly poly_volt_to_N = { > +static const struct pvt_poly __maybe_unused poly_volt_to_N = { > .total_divider = 10, > .terms = { > {1, 18658, 1000, 1},
diff --git a/drivers/hwmon/bt1-pvt.c b/drivers/hwmon/bt1-pvt.c index 1a9772fb1f73..8709b3f54086 100644 --- a/drivers/hwmon/bt1-pvt.c +++ b/drivers/hwmon/bt1-pvt.c @@ -64,7 +64,7 @@ static const struct pvt_sensor_info pvt_info[] = { * 48380, * where T = [-48380, 147438] mC and N = [0, 1023]. */ -static const struct pvt_poly poly_temp_to_N = { +static const struct pvt_poly __maybe_unused poly_temp_to_N = { .total_divider = 10000, .terms = { {4, 18322, 10000, 10000}, @@ -96,7 +96,7 @@ static const struct pvt_poly poly_N_to_temp = { * N = (18658e-3*V - 11572) / 10, * V = N * 10^5 / 18658 + 11572 * 10^4 / 18658. */ -static const struct pvt_poly poly_volt_to_N = { +static const struct pvt_poly __maybe_unused poly_volt_to_N = { .total_divider = 10, .terms = { {1, 18658, 1000, 1},
Clang-based kernel building with W=1 warns that some static const variables are unused: drivers/hwmon/bt1-pvt.c:67:30: warning: unused variable 'poly_temp_to_N' [-Wunused-const-variable] static const struct pvt_poly poly_temp_to_N = { ^ drivers/hwmon/bt1-pvt.c:99:30: warning: unused variable 'poly_volt_to_N' [-Wunused-const-variable] static const struct pvt_poly poly_volt_to_N = { ^ Indeed these polynomials are utilized only when the PVT sensor alarms are enabled. In that case they are used to convert the temperature and voltage alarm limits from normal quantities (Volts and degree Celsius) to the sensor data representation N = [0, 1023]. Otherwise when alarms are disabled the driver only does the detected data conversion to the human readable form and doesn't need that polynomials defined. So let's mark the Temp-to-N and Volt-to-N polynomials with __maybe_unused attribute. Note gcc with W=1 doesn't notice the problem. Fixes: 87976ce2825d ("hwmon: Add Baikal-T1 PVT sensor driver") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> --- Link: https://lore.kernel.org/linux-hwmon/20200602091219.24404-1-Sergey.Semin@baikalelectronics.ru Changelog v2: - Repalce if-defs with __maybe_unused attribute. --- drivers/hwmon/bt1-pvt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)