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Date:   Sat, 8 Aug 2020 08:53:29 +0200
From:   Stephen Kitt <steve@sk2.org>
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     Jean Delvare <jdelvare@suse.com>, linux-hwmon@vger.kernel.org,
        linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
        Wolfram Sang <wsa@kernel.org>
Subject: Re: [PATCH v3] hwmon/pmbus: use simple i2c probe function
Message-ID: <20200808085329.4713bf38@heffalump.sk2.org>
In-Reply-To: <20200807210707.7dd1d9b9@heffalump.sk2.org>
References: <20200807173231.GA47449@roeck-us.net>
        <20200807210707.7dd1d9b9@heffalump.sk2.org>
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On Fri, 7 Aug 2020 21:07:07 +0200, Stephen Kitt <steve@sk2.org> wrote:

> On Fri, 7 Aug 2020 10:32:31 -0700, Guenter Roeck <linux@roeck-us.net> wro=
te:
> > On Fri, Aug 07, 2020 at 06:28:01PM +0200, Stephen Kitt wrote: =20
> > > =20
> > > -static int ltc2978_probe(struct i2c_client *client,
> > > -			 const struct i2c_device_id *id)
> > > +static int ltc2978_probe(struct i2c_client *client)
> > >  {
> > >  	int i, chip_id;
> > >  	struct ltc2978_data *data;
> > > @@ -670,10 +669,10 @@ static int ltc2978_probe(struct i2c_client
> > > *client, return chip_id;
> > > =20
> > >  	data->id =3D chip_id;
> > > -	if (data->id !=3D id->driver_data)
> > > +	if (strcmp(client->name, ltc2978_id[data->id].name) !=3D 0)   =20
> >=20
> > I was about to apply this patch, but this is problematic: It assumes th=
at
> > __stringify(id) =3D=3D ltc2978_id[id].name and that ltc2978_id[id].driv=
er_data
> > =3D=3D id. While that is curently the case (as far as I can see), it is=
 still
> > unsafe. I think it would be much safer to use i2c_match_id() here. =20
>=20
> I=E2=80=99m not following the __stringify assumption
[...]

I get it, the code assumes there=E2=80=99s a bijection between the set of n=
ames and
the set of driver_data values. So effectively we can=E2=80=99t log the dete=
cted name
based on the chip_id...

Regards,

Stephen

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