Re: [PATCH] HID: hid-sensor-custom: remove useless variable

From: srinivas pandruvada
Date: Mon Apr 12 2021 - 18:27:17 EST


On Mon, 2021-04-12 at 11:20 +0100, Jonathan Cameron wrote:
> On Sun, 11 Apr 2021 09:06:35 -0700
> Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
>
> > On Sun, 2021-04-11 at 14:56 +0100, Jonathan Cameron wrote:
> > > On Fri, 09 Apr 2021 11:19:12 -0700
> > > Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
> > >
> > > > On Fri, 2021-04-09 at 15:15 +0800, Jiapeng Chong wrote:
> > > > > Fix the following gcc warning:
> > > > >
> > > > > drivers/hid/hid-sensor-custom.c:400:7: warning: variable
> > > > > ‘ret’
> > > > > set
> > > > > but
> > > > > not used [-Wunused-but-set-variable].
> > > > >
> > > > > Reported-by: Abaci Robot <abaci@xxxxxxxxxxxxxxxxx>
> > > > > Signed-off-by: Jiapeng Chong <jiapeng.chong@xxxxxxxxxxxxxxxxx
> > > > > >
> > > > Acked-by: Srinivas Pandruvada <
> > > > srinivas.pandruvada@xxxxxxxxxxxxxxx
> > >
> > > Perhaps better to return ret if it is non zero?
> > > I can't immediately figure out if there is a reason we know that
> > > can't
> > > happen.
> > Only time it can fail when there is no report descriptor or the
> > field
> > index is >= report->maxfield.
> > But since the attribute is registered from the report descriptor
> > and
> > index, this can't happen.
> > But we can enhance sensor_hub_set_feature() to fail when
> > hid_set_field() fails. There is one case where field-
> > >logical_minimum
> > < 0 and value is out of range.
>
> I'll go with what you think. Apply as is, or handle the
> return value because we might at some later date return an error that
> can actually happen from here?
>
I will send you a patch this week to handle error condition.

Thanks,
Srinivas

> Jonathan
>
> > Thanks,
> > Srinivas
> >
> >
> > > Jonathan
> > >
> > > > > ---
> > > > > drivers/hid/hid-sensor-custom.c | 5 ++---
> > > > > 1 file changed, 2 insertions(+), 3 deletions(-)
> > > > >
> > > > > diff --git a/drivers/hid/hid-sensor-custom.c
> > > > > b/drivers/hid/hid-
> > > > > sensor-custom.c
> > > > > index 2628bc5..e430673 100644
> > > > > --- a/drivers/hid/hid-sensor-custom.c
> > > > > +++ b/drivers/hid/hid-sensor-custom.c
> > > > > @@ -397,15 +397,14 @@ static ssize_t store_value(struct
> > > > > device
> > > > > *dev,
> > > > > struct device_attribute *attr,
> > > > >
> > > > > if (!strncmp(name, "value", strlen("value"))) {
> > > > > u32 report_id;
> > > > > - int ret;
> > > > >
> > > > > if (kstrtoint(buf, 0, &value) != 0)
> > > > > return -EINVAL;
> > > > >
> > > > > report_id = sensor_inst-
> > > > > >fields[field_index].attribute.
> > > > >
> > > > > report_
> > > > > id;
> > > > > - ret = sensor_hub_set_feature(sensor_inst-
> > > > > >hsdev,
> > > > > report_id,
> > > > > - index,
> > > > > sizeof(value),
> > > > > &value);
> > > > > + sensor_hub_set_feature(sensor_inst->hsdev,
> > > > > report_id,
> > > > > index,
> > > > > + sizeof(value), &value);
> > > > > } else
> > > > > return -EINVAL;
> > > > >