Re: [PATCH] hwmon: (scpi) skip unsupported sensors properly

[Sudeep Holla]

On 28/10/15 15:39, Punit Agrawal wrote:
> Hi Sudeep,
>
> Sudeep Holla <sudeep.holla@xxxxxxx> writes:
>
> > Currently it's assumed that firmware exports only the class of sensors
> > supported by the driver. However with newer firmware or SCPI protocol
> > revision, support for newer classes of sensors can be present.
> >
> > The driver fails to probe with the following warning if an unsupported
> > class of sensor is encountered in the firmware.
> >
> > sysfs: cannot create duplicate filename
> > 	'/devices/platform/scpi/scpi:sensors/hwmon/hwmon0/'
> > ------------[ cut here ]------------
> > WARNING: at fs/sysfs/dir.c:31
> > Modules linked in:
> >
> > CPU: 0 PID: 6 Comm: kworker/u12:0 Not tainted 4.3.0-rc7 #137
> > Hardware name: ARM Juno development board (r0) (DT)
> > Workqueue: deferwq deferred_probe_work_func
> > PC is at sysfs_warn_dup+0x54/0x78
> > LR is at sysfs_warn_dup+0x54/0x78
>
> Thanks for spotting the issue and the fix below. Some comments below.
>
>
> > This patch fixes the above issue by skipping through the unsupported
> > class of SCPI sensors.
> >
> > Fixes: 68acc77a2d51 ("hwmon: Support thermal zones registration for SCP temperature sensors")
> > Fixes: ea98b29a05e9 ("hwmon: Support sensors exported via ARM SCP interface")
> > Cc: Punit Agrawal <punit.agrawal@xxxxxxx>
> > Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
>
>
> > ---
> >   drivers/hwmon/scpi-hwmon.c | 21 +++++++++++----------
> >   1 file changed, 11 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/hwmon/scpi-hwmon.c b/drivers/hwmon/scpi-hwmon.c
> > index 2c1241bbf9af..5b80cd7f5c86 100644
> > --- a/drivers/hwmon/scpi-hwmon.c
> > +++ b/drivers/hwmon/scpi-hwmon.c
>
> [...]
>
> > @@ -234,9 +235,9 @@ static int scpi_hwmon_probe(struct platform_device *pdev)
> >   			goto unregister_tzd;
> >   		}
> >
> > -		zone->sensor_id = i;
> > +		zone->sensor_id = sensor->info.sensor_id;
>
> This shouldn't be changed . The zone->sensor_id is used to access the sensor
> data in scpi_read_temp and will use the wrong index with the above
> change. Which means...

Ah, right thanks for spotting this.

> >   		zone->scpi_sensors = scpi_sensors;
> > -		zone->tzd = thermal_zone_of_sensor_register(dev, i, zone,
> > +		zone->tzd = thermal_zone_of_sensor_register(dev, zone->sensor_id, zone,
> >   							    &scpi_sensor_ops);
>
> ... the thermal zone registration should use sensor->info.sensor_id
> instead of zone->sensor_id.
>
> With these two changes, feel free to add
>
>       Reviewed-by: Punit Agrawal <punit.agrawal@xxxxxxx>

Will update the patch with these 2 changes and resend. Thanks for the
review.

--
Regards,
Sudeep
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/