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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Tue, 14 Jun 2022 12:58:21 +0200
Message-ID: <CAHp75VeYK=oCbbBVp01_b5LK_FqAo4F_bic9Me4Y6PpfFnDU6g@mail.gmail.com>
Subject: Re: [v6 08/14] iio: imu: add Bosch Sensortec BNO055 core driver
To:     Andrea Merello <Andrea.Merello@iit.it>
Cc:     Jonathan Cameron <jic23@kernel.org>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        linux-iio <linux-iio@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Rob Herring <robh+dt@kernel.org>,
        Matt Ranostay <matt.ranostay@konsulko.com>,
        Alexandru Ardelean <ardeleanalex@gmail.com>,
        jmondi <jacopo@jmondi.org>
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On Tue, Jun 14, 2022 at 11:11 AM Andrea Merello <Andrea.Merello@iit.it> wro=
te:

...

> >> +                                /* G:   2,    4,    8,    16 */
> >
> >Indentation of this comment is a bit off.
> >
> >> +static int bno055_acc_range_vals[] =3D {1962, 3924, 7848, 15696};
> >
> >Perhaps split this to 4 lines and put the comment on top of the third li=
ne?
>
> Not sure what you mean here, sorry. May you elaborate or provide an examp=
le, please?

static int ... [] =3D {
    /* Comment goes here */
   value1, value2, ..., valueN,
};

...

> >> +static void bno055_debugfs_init(struct iio_dev *iio_dev)
> >> +{
> >> +       struct bno055_priv *priv =3D iio_priv(iio_dev);
> >> +
> >> +       priv->debugfs =3D debugfs_create_file("firmware_version", 0400=
,
> >> +                                           iio_get_debugfs_dentry(iio=
_dev),
> >> +                                           priv, &bno055_fw_version_o=
ps);
> >
> >> +       devm_add_action_or_reset(priv->dev, bno055_debugfs_remove, pri=
v->debugfs);
> >
> >Shouldn't we report the potential error here? It's not directly
> >related to debugfs, but something which is not directly related.
>
> The error eventually comes out from something that has nothing to do with=
 debugs per se (i.e. the devm stuff), but it will only affect debugfs indee=
d.
>
> Assuming that we don't want to make the whole driver fail in case debugfs=
 stuff fails (see last part of the comment above debugfs_create_file() impl=
ementation), and given that the devm_add_action_or_reset(), should indeed "=
reset" in case of failure (i.e. we should be in a clean situation anyway), =
I would say it should be OK not to propagate the error and let things go on=
.

As I said, it's not directly related to debugfs. Here is the resource
leak possible or bad things happen if you probe the driver, that fails
to add this call for removal, remove it, and try to insert again, in
such case the debugfs will be stale.

> However we can add a dev_warn() to report what happened.

Not sure if it would suffice, I leave it to Jonathan.

--=20
With Best Regards,
Andy Shevchenko