On Tue, 2012-03-27 at 03:19 -0400, Jean Delvare wrote:
> Hi Guenter,
>
> On Sat, 24 Mar 2012 08:56:49 -0700, Guenter Roeck wrote:
> > Some configurations produce the following compile warning:
> >
> > drivers/hwmon/adm1031.c: In function 'set_fan_auto_channel':
> > drivers/hwmon/adm1031.c:292: warning: 'reg' may be used uninitialized in this function
> >
> > While this is a false positive, it can easily be fixed by overloading the return
> > value from get_fan_auto_nearest with both register value and error return code
> > (the register value is never negative). Coincidentially, that also reduces
> > module size by a few bytes.
> >
> > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > ---
> > drivers/hwmon/adm1031.c | 21 ++++++++-------------
> > 1 files changed, 8 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/hwmon/adm1031.c b/drivers/hwmon/adm1031.c
> > index ff37363..c58acb4 100644
> > --- a/drivers/hwmon/adm1031.c
> > +++ b/drivers/hwmon/adm1031.c
> > @@ -233,18 +233,15 @@ static const auto_chan_table_t auto_channel_select_table_adm1030 = {
> > * nearest match if no exact match where found.
> > */
> > static int
> > -get_fan_auto_nearest(struct adm1031_data *data,
> > - int chan, u8 val, u8 reg, u8 *new_reg)
> > +get_fan_auto_nearest(struct adm1031_data *data, int chan, u8 val, u8 reg)
> > {
> > int i;
> > int first_match = -1, exact_match = -1;
> > u8 other_reg_val =
> > (*data->chan_select_table)[FAN_CHAN_FROM_REG(reg)][chan ? 0 : 1];
> >
> > - if (val == 0) {
> > - *new_reg = 0;
> > + if (val == 0)
> > return 0;
> > - }
> >
> > for (i = 0; i < 8; i++) {
> > if ((val == (*data->chan_select_table)[i][chan]) &&
> > @@ -264,13 +261,11 @@ get_fan_auto_nearest(struct adm1031_data *data,
> > }
> >
> > if (exact_match >= 0)
> > - *new_reg = exact_match;
> > + return exact_match;
> > else if (first_match >= 0)
> > - *new_reg = first_match;
> > - else
> > - return -EINVAL;
> > + return first_match;
> >
> > - return 0;
> > + return -EINVAL;
> > }
> >
> > static ssize_t show_fan_auto_channel(struct device *dev,
> > @@ -301,10 +296,10 @@ set_fan_auto_channel(struct device *dev, struct device_attribute *attr,
> >
> > mutex_lock(&data->update_lock);
> >
> > - ret = get_fan_auto_nearest(data, nr, val, data->conf1, ®);
> > - if (ret) {
> > + reg = get_fan_auto_nearest(data, nr, val, data->conf1);
> > + if (reg < 0) {
> > mutex_unlock(&data->update_lock);
> > - return ret;
> > + return reg;
> > }
> > data->conf1 = FAN_CHAN_TO_REG(reg, data->conf1);
> > if ((data->conf1 & ADM1031_CONF1_AUTO_MODE) ^
>
> Meep meep. reg is u8, it can't hold negative values. You must turn reg
> into an int, or do:
Me so dumb sometimes. Sent out another version of the patch.
Wonder why the compiler didn't complain about that one ...
Thanks,
Guenter
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