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From:   Alexandru Ardelean <ardeleanalex@gmail.com>
Date:   Wed, 12 May 2021 20:20:02 +0300
Message-ID: <CA+U=DsptfNDut3984MJkKckgWBhNd_0p17RfpidEXwYhMRfxtg@mail.gmail.com>
Subject: Re: [PATCH 2/2] staging: iio: cdc: ad7746: avoid overwrite of num_channels
To:     Lucas Stankus <lucas.p.stankus@gmail.com>
Cc:     Lars-Peter Clausen <lars@metafoo.de>,
        "Hennerich, Michael" <Michael.Hennerich@analog.com>,
        Jonathan Cameron <jic23@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-iio <linux-iio@vger.kernel.org>,
        linux-staging@lists.linux.dev, LKML <linux-kernel@vger.kernel.org>
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On Tue, May 11, 2021 at 11:55 PM Lucas Stankus
<lucas.p.stankus@gmail.com> wrote:
>
> AD7745 devices don't have the CIN2 pins and therefore can't handle related
> channels. Forcing the number of AD7746 channels may lead to enabling more
> channels than what the hardware actually supports.
> Avoid num_channels being overwritten after first assignment.
>
> Signed-off-by: Lucas Stankus <lucas.p.stankus@gmail.com>
> ---
>  drivers/staging/iio/cdc/ad7746.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/drivers/staging/iio/cdc/ad7746.c b/drivers/staging/iio/cdc/ad7746.c
> index e03d010b2f4c..9e0da43b2871 100644
> --- a/drivers/staging/iio/cdc/ad7746.c
> +++ b/drivers/staging/iio/cdc/ad7746.c
> @@ -693,7 +693,6 @@ static int ad7746_probe(struct i2c_client *client,
>                 indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
>         else
>                 indio_dev->num_channels =  ARRAY_SIZE(ad7746_channels) - 2;
> -       indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);

ohh; good catch

this falls into the category of a fix, so a Fixes tag is required;
this looks so old, that i did not bother tracking it before
83e416f458d53  [which is 2011]

so, maybe something like:

Fixes: 83e416f458d53 ("staging: iio: adc: Replace, rewrite ad7745 from
scratch.")

>         indio_dev->modes = INDIO_DIRECT_MODE;
>
>         if (pdata) {
> --
> 2.31.1
>