Re: [PATCH 1/3] IIO: st_accel_i2c.c: Use fallback if DT/ACPI enum failed

[Nikolaus Voss]

On Sat, 30 Jun 2018, Jonathan Cameron wrote:

> On Fri, 29 Jun 2018 10:10:10 +0200
> Nikolaus Voss <nikolaus.voss@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> > Currently, the driver bails out if not explicitly referred to in
> > DT or ACPI tables. This prevents fallback mechanisms from coming
> > into effect, e.g. I2C device ID table match via DT or ACPI
> > PRP0001 HID. However DT/ACPI enum should take precedence over
> > the fallback, so evaluate that first.
> >
> > Signed-off-by: Nikolaus Voss <nikolaus.voss@xxxxxxxxxxxxxxxxxxxxx>
>
> Is the change to probe_new actually related to the rest of the change?
>
> I can't immediately see why...  If not I would prefer that as a separate
> change.

Well, it is, because the id table pointer of the old probe() is not 
used any more.

> > ---
> >  drivers/iio/accel/st_accel_i2c.c | 21 ++++++++++++---------
> >  1 file changed, 12 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/iio/accel/st_accel_i2c.c b/drivers/iio/accel/st_accel_i2c.c
> > index 6bdec8c451e0..e360da407027 100644
> > --- a/drivers/iio/accel/st_accel_i2c.c
> > +++ b/drivers/iio/accel/st_accel_i2c.c
> > @@ -138,8 +138,7 @@ static const struct i2c_device_id st_accel_id_table[] = {
> >  };
> >  MODULE_DEVICE_TABLE(i2c, st_accel_id_table);
> >
> > -static int st_accel_i2c_probe(struct i2c_client *client,
> > -						const struct i2c_device_id *id)
> > +static int st_accel_i2c_probe(struct i2c_client *client)
> >  {
> >  	struct iio_dev *indio_dev;
> >  	struct st_sensor_data *adata;
> > @@ -156,14 +155,18 @@ static int st_accel_i2c_probe(struct i2c_client *client,
> >  					 client->name, sizeof(client->name));
> >  	} else if (ACPI_HANDLE(&client->dev)) {
> >  		ret = st_sensors_match_acpi_device(&client->dev);
> > -		if ((ret < 0) || (ret >= ST_ACCEL_MAX))
> > -			return -ENODEV;
> > -
> > -		strlcpy(client->name, st_accel_id_table[ret].name,
> > +		if ((ret >= 0) && (ret < ST_ACCEL_MAX))
> > +			strlcpy(client->name, st_accel_id_table[ret].name,
> >  				sizeof(client->name));
> > -	} else if (!id)
> > -		return -ENODEV;
> > +	}
> >
> > +	/*
> > +	 * If OF and ACPI enumeration failed, there could still be platform
> > +	 * information via fallback enumeration or explicit instantiation, so
> > +	 * check if id table has been matched via client->name.
> > +	 */
> > +	if (!client->name)
> > +		return -ENODEV;
> >
> >  	st_sensors_i2c_configure(indio_dev, client, adata);
> >
> > @@ -187,7 +190,7 @@ static struct i2c_driver st_accel_driver = {
> >  		.of_match_table = of_match_ptr(st_accel_of_match),
> >  		.acpi_match_table = ACPI_PTR(st_accel_acpi_match),
> >  	},
> > -	.probe = st_accel_i2c_probe,
> > +	.probe_new = st_accel_i2c_probe,
> >  	.remove = st_accel_i2c_remove,
> >  	.id_table = st_accel_id_table,
> >  };