diff mbox

hwmon: (scpi) skip unsupported sensors properly

Message ID 1446041283-19702-1-git-send-email-sudeep.holla@arm.com
State Superseded
Headers show

Commit Message

Sudeep Holla Oct. 28, 2015, 2:08 p.m. UTC
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

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@arm.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

---
 drivers/hwmon/scpi-hwmon.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

--
1.9.1

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Comments

Punit Agrawal Oct. 28, 2015, 3:39 p.m. UTC | #1
Hi Sudeep,

Sudeep Holla <sudeep.holla@arm.com> 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@arm.com>

> Cc: Guenter Roeck <linux@roeck-us.net>

> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>



> ---

>  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...

>  		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@arm.com>


>  		/*

>  		 * The call to thermal_zone_of_sensor_register returns

> --

> 1.9.1

>

> --

> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in

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Sudeep Holla Oct. 28, 2015, 3:58 p.m. UTC | #2
On 28/10/15 15:39, Punit Agrawal wrote:
> Hi Sudeep,

>

> Sudeep Holla <sudeep.holla@arm.com> 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@arm.com>

>> Cc: Guenter Roeck <linux@roeck-us.net>

>> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

>

>

>> ---

>>   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@arm.com>


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

-- 
Regards,
Sudeep
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diff mbox

Patch

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
@@ -117,7 +117,7 @@  static int scpi_hwmon_probe(struct platform_device *pdev)
 	struct scpi_ops *scpi_ops;
 	struct device *hwdev, *dev = &pdev->dev;
 	struct scpi_sensors *scpi_sensors;
-	int ret;
+	int ret, idx;

 	scpi_ops = get_scpi_ops();
 	if (!scpi_ops)
@@ -146,8 +146,8 @@  static int scpi_hwmon_probe(struct platform_device *pdev)

 	scpi_sensors->scpi_ops = scpi_ops;

-	for (i = 0; i < nr_sensors; i++) {
-		struct sensor_data *sensor = &scpi_sensors->data[i];
+	for (i = 0, idx = 0; i < nr_sensors; i++) {
+		struct sensor_data *sensor = &scpi_sensors->data[idx];

 		ret = scpi_ops->sensor_get_info(i, &sensor->info);
 		if (ret)
@@ -183,7 +183,7 @@  static int scpi_hwmon_probe(struct platform_device *pdev)
 			num_power++;
 			break;
 		default:
-			break;
+			continue;
 		}

 		sensor->dev_attr_input.attr.mode = S_IRUGO;
@@ -194,11 +194,12 @@  static int scpi_hwmon_probe(struct platform_device *pdev)
 		sensor->dev_attr_label.show = scpi_show_label;
 		sensor->dev_attr_label.attr.name = sensor->label;

-		scpi_sensors->attrs[i << 1] = &sensor->dev_attr_input.attr;
-		scpi_sensors->attrs[(i << 1) + 1] = &sensor->dev_attr_label.attr;
+		scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr;
+		scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr;

-		sysfs_attr_init(scpi_sensors->attrs[i << 1]);
-		sysfs_attr_init(scpi_sensors->attrs[(i << 1) + 1]);
+		sysfs_attr_init(scpi_sensors->attrs[idx << 1]);
+		sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]);
+		idx++;
 	}

 	scpi_sensors->group.attrs = scpi_sensors->attrs;
@@ -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;
 		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 call to thermal_zone_of_sensor_register returns