On Tue, Jun 02, 2020 at 12:12:19PM +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 declare > the Temp-to-N and Volt-to-N polynomials only if the PVT alarms are > switched on at compile-time. > > Note gcc with W=1 doesn't notice the problem. > > Fixes: 87976ce2825d ("hwmon: Add Baikal-T1 PVT sensor driver") > Reported-by: kbuild test robot <l...@intel.com> > Signed-off-by: Serge Semin <sergey.se...@baikalelectronics.ru> > Cc: Maxim Kaurkin <maxim.kaur...@baikalelectronics.ru> > Cc: Alexey Malahov <alexey.mala...@baikalelectronics.ru>
I don't really like the added #if. Can you use __maybe_unused instead ? Thanks, Guenter > --- > drivers/hwmon/bt1-pvt.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/hwmon/bt1-pvt.c b/drivers/hwmon/bt1-pvt.c > index 1a9772fb1f73..1a5212c04549 100644 > --- a/drivers/hwmon/bt1-pvt.c > +++ b/drivers/hwmon/bt1-pvt.c > @@ -64,6 +64,7 @@ static const struct pvt_sensor_info pvt_info[] = { > * 48380, > * where T = [-48380, 147438] mC and N = [0, 1023]. > */ > +#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS) > static const struct pvt_poly poly_temp_to_N = { > .total_divider = 10000, > .terms = { > @@ -74,6 +75,7 @@ static const struct pvt_poly poly_temp_to_N = { > {0, 1720400, 1, 1} > } > }; > +#endif /* CONFIG_SENSORS_BT1_PVT_ALARMS */ > > static const struct pvt_poly poly_N_to_temp = { > .total_divider = 1, > @@ -96,6 +98,7 @@ static const struct pvt_poly poly_N_to_temp = { > * N = (18658e-3*V - 11572) / 10, > * V = N * 10^5 / 18658 + 11572 * 10^4 / 18658. > */ > +#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS) > static const struct pvt_poly poly_volt_to_N = { > .total_divider = 10, > .terms = { > @@ -103,6 +106,7 @@ static const struct pvt_poly poly_volt_to_N = { > {0, -11572, 1, 1} > } > }; > +#endif /* CONFIG_SENSORS_BT1_PVT_ALARMS */ > > static const struct pvt_poly poly_N_to_volt = { > .total_divider = 10,