On Wed, Jul 18, 2018 at 12:55:03PM +0530, Amit Kucheria wrote: > The current code will always return 0xffffffff in case of negative > temperatures due to a bug in how the binary sign extension is being done. > > Use sign_extend32() instead. > > Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx> > --- > drivers/thermal/qcom/tsens-v2.c | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) > > diff --git a/drivers/thermal/qcom/tsens-v2.c b/drivers/thermal/qcom/tsens-v2.c > index 908e3dc..46abc21 100644 > --- a/drivers/thermal/qcom/tsens-v2.c > +++ b/drivers/thermal/qcom/tsens-v2.c > @@ -5,19 +5,20 @@ > */ > > #include <linux/regmap.h> > +#include <linux/bitops.h> > #include "tsens.h" > > #define STATUS_OFFSET 0xa0 > #define LAST_TEMP_MASK 0xfff > #define STATUS_VALID_BIT BIT(21) > -#define CODE_SIGN_BIT BIT(11) > > static int get_temp_tsens_v2(struct tsens_device *tmdev, int id, int *temp) > { > struct tsens_sensor *s = &tmdev->sensor[id]; > u32 code; > unsigned int status_reg; > - int last_temp = 0, last_temp2 = 0, last_temp3 = 0, ret; > + u32 last_temp = 0, last_temp2 = 0, last_temp3 = 0; > + int ret; > > status_reg = tmdev->tm_offset + STATUS_OFFSET + s->hw_id * 4; > ret = regmap_read(tmdev->map, status_reg, &code); > @@ -54,12 +55,8 @@ static int get_temp_tsens_v2(struct tsens_device *tmdev, int id, int *temp) > else if (last_temp2 == last_temp3) > last_temp = last_temp3; > done: > - /* Code sign bit is the sign extension for a negative value */ > - if (last_temp & CODE_SIGN_BIT) > - last_temp |= ~CODE_SIGN_BIT; > - > - /* Temperatures are in deciCelicius */ > - *temp = last_temp * 100; > + /* Convert temperatures to milliCelicius */ nits: s/temperatures/temperature/ s/milliCelicius/milliCelsius/ > + *temp = sign_extend32(last_temp, fls(LAST_TEMP_MASK) - 1) * 100; > > return 0; > } Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html