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[PATCH 3/3] hwmon: scmi: Enhance error reporting with dev_err_probe

a.shimko posted 3 patches 2 months ago
[PATCH 3/3] hwmon: scmi: Enhance error reporting with dev_err_probe
Posted by a.shimko 2 months ago 
From: Artem Shimko <artyom.shimko@gmail.com>

Replace error returns with dev_err_probe() throughout driver:
- Add descriptive error messages for all failure cases
- Include relevant context (sensor IDs, types etc)
- Standardize error reporting format

Improved messages include:
- "No valid sensor info for index %d"
- "Failed to allocate channel info array"
- "SCMI protocol ops not initialized"

Signed-off-by: Artem Shimko <artyom.shimko@gmail.com>
---
 drivers/hwmon/scmi-hwmon.c | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
index d03174922e65..081502418dfa 100644
--- a/drivers/hwmon/scmi-hwmon.c
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -240,26 +240,36 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 	struct scmi_protocol_handle *ph;
 
 	if (!handle)
-		return -ENODEV;
+		return dev_err_probe(dev, -ENODEV, "SCMI device handle is NULL\n");
 
 	sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
-	if (IS_ERR(sensor_ops))
-		return PTR_ERR(sensor_ops);
+	if (IS_ERR_OR_NULL(sensor_ops)) {
+		if (IS_ERR(sensor_ops))
+			return dev_err_probe(dev, PTR_ERR(sensor_ops),
+					     "SCMI sensor protocol acquisition failed\n");
+		return dev_err_probe(dev, -EPROTO,
+				     "SCMI sensor protocol ops structure unexpectedly NULL\n");
+	}
+
+	if (!sensor_ops->info_get || !sensor_ops->count_get)
+		return dev_err_probe(dev, -ENOENT,
+				     "SCMI sensor protocol operations are not initialized\n");
 
 	nr_sensors = sensor_ops->count_get(ph);
 	if (!nr_sensors)
-		return -EIO;
+		return dev_err_probe(dev, -EIO, "No sensors found\n");
 
 	scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);
 	if (!scmi_sensors)
-		return -ENOMEM;
+		return dev_err_probe(dev, -ENOMEM, "Failed to allocate scmi_sensors structure\n");
 
 	scmi_sensors->ph = ph;
 
 	for (i = 0; i < nr_sensors; i++) {
 		sensor = sensor_ops->info_get(ph, i);
 		if (!sensor)
-			return -EINVAL;
+			return dev_err_probe(dev, -EINVAL,
+					     "Failed to get sensor info for sensor %d\n", i);
 
 		switch (sensor->type) {
 		case TEMPERATURE_C:
@@ -285,12 +295,12 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 	scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan),
 				       GFP_KERNEL);
 	if (!scmi_hwmon_chan)
-		return -ENOMEM;
+		return dev_err_probe(dev, -ENOMEM, "Failed to allocate channel info array\n");
 
 	ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci),
 				   GFP_KERNEL);
 	if (!ptr_scmi_ci)
-		return -ENOMEM;
+		return dev_err_probe(dev, -ENOMEM, "Failed to allocate channel info pointers\n");
 
 	scmi_chip_info.info = ptr_scmi_ci;
 	chip_info = &scmi_chip_info;
@@ -307,7 +317,8 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 			devm_kcalloc(dev, nr_count[type],
 				     sizeof(*scmi_sensors->info), GFP_KERNEL);
 		if (!scmi_sensors->info[type])
-			return -ENOMEM;
+			return dev_err_probe(dev, -ENOMEM,
+					     "Failed to allocate sensor info for type %d\n", type);
 	}
 
 	for (i = nr_sensors - 1; i >= 0 ; i--) {
@@ -336,7 +347,7 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 						     scmi_sensors, chip_info,
 						     NULL);
 	if (IS_ERR(hwdev))
-		return PTR_ERR(hwdev);
+		return dev_err_probe(dev, PTR_ERR(hwdev), "Failed to register hwmon device\n");
 
 	for (i = 0; i < nr_count_temp; i++) {
 		int ret;
@@ -352,7 +363,9 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 		ret = scmi_thermal_sensor_register(dev, ph, sensor);
 		if (ret) {
 			if (ret == -ENOMEM)
-				return ret;
+				return dev_err_probe(dev, ret,
+						     "Failed to allocate memory for thermal zone\n");
+
 			dev_warn(dev,
 				 "Thermal zone misconfigured for %s. err=%d\n",
 				 sensor->name, ret);
-- 
2.43.0
Re: [PATCH 3/3] hwmon: scmi: Enhance error reporting with dev_err_probe
Posted by Guenter Roeck 2 months ago 
On 8/5/25 05:43, a.shimko wrote:
> From: Artem Shimko <artyom.shimko@gmail.com>
> 
> Replace error returns with dev_err_probe() throughout driver:
> - Add descriptive error messages for all failure cases
> - Include relevant context (sensor IDs, types etc)
> - Standardize error reporting format
> 
> Improved messages include:
> - "No valid sensor info for index %d"
> - "Failed to allocate channel info array"
> - "SCMI protocol ops not initialized"
> 
> Signed-off-by: Artem Shimko <artyom.shimko@gmail.com>
> ---
>   drivers/hwmon/scmi-hwmon.c | 35 ++++++++++++++++++++++++-----------
>   1 file changed, 24 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
> index d03174922e65..081502418dfa 100644
> --- a/drivers/hwmon/scmi-hwmon.c
> +++ b/drivers/hwmon/scmi-hwmon.c
> @@ -240,26 +240,36 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>   	struct scmi_protocol_handle *ph;
>   
>   	if (!handle)
> -		return -ENODEV;
> +		return dev_err_probe(dev, -ENODEV, "SCMI device handle is NULL\n");

-ENODEV is not supposed to log an error message.

>   
>   	sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
> -	if (IS_ERR(sensor_ops))
> -		return PTR_ERR(sensor_ops);
> +	if (IS_ERR_OR_NULL(sensor_ops)) {

This never returns NULL, and AFAIS no other driver checks for it.
Why add this unnecessary check ?

> +		if (IS_ERR(sensor_ops))
> +			return dev_err_probe(dev, PTR_ERR(sensor_ops),
> +					     "SCMI sensor protocol acquisition failed\n");
> +		return dev_err_probe(dev, -EPROTO,
> +				     "SCMI sensor protocol ops structure unexpectedly NULL\n");
> +	}
> +
> +	if (!sensor_ops->info_get || !sensor_ops->count_get)
> +		return dev_err_probe(dev, -ENOENT,
> +				     "SCMI sensor protocol operations are not initialized\n");

It is not this driver's responsibility to validate sensor_ops.

>   
>   	nr_sensors = sensor_ops->count_get(ph);
>   	if (!nr_sensors)
> -		return -EIO;
> +		return dev_err_probe(dev, -EIO, "No sensors found\n");
>   
>   	scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);
>   	if (!scmi_sensors)
> -		return -ENOMEM;
> +		return dev_err_probe(dev, -ENOMEM, "Failed to allocate scmi_sensors structure\n");

-ENOMEM is not supposed to log an error message.

>   
>   	scmi_sensors->ph = ph;
>   
>   	for (i = 0; i < nr_sensors; i++) {
>   		sensor = sensor_ops->info_get(ph, i);
>   		if (!sensor)
> -			return -EINVAL;
> +			return dev_err_probe(dev, -EINVAL,
> +					     "Failed to get sensor info for sensor %d\n", i);
>   
>   		switch (sensor->type) {
>   		case TEMPERATURE_C:
> @@ -285,12 +295,12 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>   	scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan),
>   				       GFP_KERNEL);
>   	if (!scmi_hwmon_chan)
> -		return -ENOMEM;
> +		return dev_err_probe(dev, -ENOMEM, "Failed to allocate channel info array\n");

Same as above.

>   
>   	ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci),
>   				   GFP_KERNEL);
>   	if (!ptr_scmi_ci)
> -		return -ENOMEM;
> +		return dev_err_probe(dev, -ENOMEM, "Failed to allocate channel info pointers\n");

Same as above.

>   
>   	scmi_chip_info.info = ptr_scmi_ci;
>   	chip_info = &scmi_chip_info;
> @@ -307,7 +317,8 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>   			devm_kcalloc(dev, nr_count[type],
>   				     sizeof(*scmi_sensors->info), GFP_KERNEL);
>   		if (!scmi_sensors->info[type])
> -			return -ENOMEM;
> +			return dev_err_probe(dev, -ENOMEM,
> +					     "Failed to allocate sensor info for type %d\n", type);

And again.

>   	}
>   
>   	for (i = nr_sensors - 1; i >= 0 ; i--) {
> @@ -336,7 +347,7 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>   						     scmi_sensors, chip_info,
>   						     NULL);
>   	if (IS_ERR(hwdev))
> -		return PTR_ERR(hwdev);
> +		return dev_err_probe(dev, PTR_ERR(hwdev), "Failed to register hwmon device\n");
>   
>   	for (i = 0; i < nr_count_temp; i++) {
>   		int ret;
> @@ -352,7 +363,9 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>   		ret = scmi_thermal_sensor_register(dev, ph, sensor);
>   		if (ret) {
>   			if (ret == -ENOMEM)
> -				return ret;
> +				return dev_err_probe(dev, ret,
> +						     "Failed to allocate memory for thermal zone\n");
> +
And again.

>   			dev_warn(dev,
>   				 "Thermal zone misconfigured for %s. err=%d\n",
>   				 sensor->name, ret);

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