On Sun, 6 Oct 2024 15:25:33 +0100
Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> On Sat, 5 Oct 2024 22:37:22 +0530
> Mohammed Anees <pvmohammedanees2003@xxxxxxxxx> wrote:
>
> > In the current implementation of the ltc2664_channel_config function,
> > a variable named span is declared and initialized to 0, intended to
> > capture the return value of the ltc2664_set_span function. However,
> > the output of ltc2664_set_span is directly assigned to chan->span,
> > leaving span unchanged. As a result, when the function later checks
> > if (span < 0), this condition will never trigger an error since
> > span remains 0, this flaw leads to ineffective error handling. The
> > current patch resolves this issue by using the ret variable for
> > getting the return value, later assigning if successful and also
> > effectively removing span variable.
> >
> > Signed-off-by: Mohammed Anees <pvmohammedanees2003@xxxxxxxxx>
> > Fixes: 4cc2fc445d2e4e63ed6bd5d310752d88d365f8e4
Hmm. I see you had a v3. For some reason that hasn't reached my inbox.
Also note the fixes tag was wrong and you've fixed that.
I've picked up v3 and applied it to the fixes-togreg branch of iio.git
and marked it for stable inclusion.
Thanks,
J
> > ---
> > v2:
> > - Using the ret variable to store the result from ltc2664_set_span
> > ---
> > drivers/iio/dac/ltc2664.c | 18 +++++++++++-------
> > 1 file changed, 11 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/iio/dac/ltc2664.c b/drivers/iio/dac/ltc2664.c
> > index 5be5345ac5c8..7dafcba7ece7 100644
> > --- a/drivers/iio/dac/ltc2664.c
> > +++ b/drivers/iio/dac/ltc2664.c
> > @@ -516,7 +516,7 @@ static int ltc2664_channel_config(struct ltc2664_state *st)
> > const struct ltc2664_chip_info *chip_info = st->chip_info;
> > struct device *dev = &st->spi->dev;
> > u32 reg, tmp[2], mspan;
> > - int ret, span = 0;
> > + int ret;
> >
> > mspan = LTC2664_MSPAN_SOFTSPAN;
> > ret = device_property_read_u32(dev, "adi,manual-span-operation-config",
> > @@ -579,20 +579,24 @@ static int ltc2664_channel_config(struct ltc2664_state *st)
> > ret = fwnode_property_read_u32_array(child, "output-range-microvolt",
> > tmp, ARRAY_SIZE(tmp));
> > if (!ret && mspan == LTC2664_MSPAN_SOFTSPAN) {
> > - chan->span = ltc2664_set_span(st, tmp[0] / 1000,
> > + ret = ltc2664_set_span(st, tmp[0] / 1000,
> > tmp[1] / 1000, reg);
> > - if (span < 0)
> > - return dev_err_probe(dev, span,
> > + if (ret < 0)
> > + return dev_err_probe(dev, ret,
> > "Failed to set span\n");
> > + else
> else is unnecessary here as we have the standard check and error and return
> if set pattern.
>
>
> > + chan->span = ret;
> > }
> >
> > ret = fwnode_property_read_u32_array(child, "output-range-microamp",
> > tmp, ARRAY_SIZE(tmp));
> > if (!ret) {
> > - chan->span = ltc2664_set_span(st, 0, tmp[1] / 1000, reg);
> > - if (span < 0)
> > - return dev_err_probe(dev, span,
> > + ret = ltc2664_set_span(st, 0, tmp[1] / 1000, reg);
> > + if (ret < 0)
> > + return dev_err_probe(dev, ret,
> > "Failed to set span\n");
> > + else
> and here.
> > + chan->span = ret;
> > }
> > }
> >
>
>
