Re: [PATCH v2] iio: adc: qcom-pm8xxx-xoadc: Remove useless condition in pm8xxx_xoadc_parse_channel()

From: Jonathan Cameron
Date: Sat Mar 18 2023 - 11:34:06 EST


On Wed, 15 Mar 2023 16:51:14 +0300
Kasumov Ruslan <xhxgldhlpfy@xxxxxxxxx> wrote:

> The left side of the loop condition never becomes false.
> hwchan cannot be NULL, because it points to elements of the
> hw_channels array that takes one of 4 predefined values:
> pm8018_xoadc_channels, pm8038_xoadc_channels,
> pm8058_xoadc_channels, pm8921_xoadc_channels.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Signed-off-by: Kasumov Ruslan <s02210418@xxxxxxxxxxxxx>

We could file this under the category of (overly) paranoid checking that
he variant structure has the hw_channels set, but given there are only 4 instances
of that it is (as you have done) easy to check.

So fair enough to drop this check.

Applied.

Thanks,

Jonathan

> ---
> v2: Removed "Fixes" tag as Andi Shyti <andi.shyti@xxxxxxxxxx> suggested.
> drivers/iio/adc/qcom-pm8xxx-xoadc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iio/adc/qcom-pm8xxx-xoadc.c b/drivers/iio/adc/qcom-pm8xxx-xoadc.c
> index eb424496ee1d..64a3aeb6261c 100644
> --- a/drivers/iio/adc/qcom-pm8xxx-xoadc.c
> +++ b/drivers/iio/adc/qcom-pm8xxx-xoadc.c
> @@ -758,7 +758,7 @@ static int pm8xxx_xoadc_parse_channel(struct device *dev,
> /* Find the right channel setting */
> chid = 0;
> hwchan = &hw_channels[0];
> - while (hwchan && hwchan->datasheet_name) {
> + while (hwchan->datasheet_name) {
> if (hwchan->pre_scale_mux == pre_scale_mux &&
> hwchan->amux_channel == amux_channel)
> break;