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    SubjectRe: [PATCH v2 11/16] hwmon: (mr75203) add protection for negative voltage value
    On Wed, Aug 17, 2022 at 05:43:16AM +0000, Eliav Farber wrote:
    > This change makes sure the returned voltage vlaue is 0 or positive.
    >
    > Signed-off-by: Eliav Farber <farbere@amazon.com>
    > ---
    > drivers/hwmon/mr75203.c | 7 +++++++
    > 1 file changed, 7 insertions(+)
    >
    > diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c
    > index 24a00339cfd8..e3191f590167 100644
    > --- a/drivers/hwmon/mr75203.c
    > +++ b/drivers/hwmon/mr75203.c
    > @@ -218,6 +218,13 @@ static int pvt_read_in(struct device *dev, u32 attr, int channel, long *val)
    > return ret;
    >
    > n &= SAMPLE_DATA_MSK;
    > +
    > + /* Voltage can't be negative */

    Who says, and what does that mean ? Under which conditions would
    the value be negative, and why would that be a problem / bug ?
    After all, negative voltages do exist.

    Guenter

    > + if (PVT_N_CONST * n < PVT_R_CONST) {
    > + *val = 0;
    > + return 0;
    > + }
    > +
    > /* Convert the N bitstream count into voltage */
    > *val = pvt->vd[channel].pre_scaler;
    > *val *= (PVT_N_CONST * n - PVT_R_CONST);

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