[PATCH v1 0/4] hwmon: scmi: Driver improvements and fixes

[PATCH v1 0/4] hwmon: scmi: Driver improvements and fixes

[Artyom Shimko]

From: Artem Shimko <artyom.shimko@gmail.com>

This patch series introduces several improvements to the SCMI HWMON driver:

1. Better handling of unsupported sensor types with debug logging
2. Fixes redundant resource management in thermal registration
3. Enhanced error reporting using dev_err_probe()
4. Added version tracking and proper contributor attribution

The changes maintain backward compatibility while improving:
- Debugging capabilities
- Error reporting clarity
- Code maintenance
- Contributor tracking

Artem Shimko (4):
  hwmon: scmi: Add default case with debug output
  hwmon: scmi: Remove redundant devm_kfree call
  hwmon: scmi: Enhance error reporting with dev_err_probe
  hwmon: scmi: Add driver version and patch author

 drivers/hwmon/scmi-hwmon.c | 50 ++++++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 13 deletions(-)

-- 
2.43.0

[PATCH v1 1/4] hwmon: scmi: Add default case with debug output

[Artyom Shimko]

From: Artem Shimko <artyom.shimko@gmail.com>

Improve handling of unsupported sensor types:
- Add default case in sensor type switch statement
- Log skipped sensors with debug information including:
  * Sensor ID
  * Sensor type
  * Sensor name (if available)
- Use rate-limited dev_dbg for safety

Debug output format:
"Skipping unsupported sensor ID:%d Type:%d (%s)"

Signed-off-by: Artem Shimko <artyom.shimko@gmail.com>
---
 drivers/hwmon/scmi-hwmon.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
index 364199b332c0..a3b5b5c0ec25 100644
--- a/drivers/hwmon/scmi-hwmon.c
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -275,6 +275,10 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 			nr_count[type]++;
 			break;
 		}
+		default:
+			dev_dbg(dev, "Skipping unsupported sensor ID:%d Type:%d (%s)\n",
+				i, sensor->type, sensor->name ? sensor->name : "unnamed");
+			continue;
 	}
 
 	if (nr_count[hwmon_temp])
@@ -323,6 +327,10 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 			idx = --nr_count[type];
 			*(scmi_sensors->info[type] + idx) = sensor;
 			break;
+		default:
+			dev_dbg(dev, "Skipping unsupported sensor ID:%d Type:%d (%s)\n",
+				i, sensor->type, sensor->name ? sensor->name : "unnamed");
+			continue;
 		}
 	}
 
-- 
2.43.0

[PATCH v1 2/4] hwmon: scmi: Remove redundant devm_kfree call

[Artyom Shimko]

From: Artem Shimko <artyom.shimko@gmail.com>

Fix potential resource management issue by:
- Removing unnecessary devm_kfree() call in error path
- Relying on devres automatic cleanup
- Preserving all error handling logic

Rationale:
- Memory was allocated with devm_kzalloc()
- devm_ thermal registration manages its own resources
- Double-free could occur during probe failure

Signed-off-by: Artem Shimko <artyom.shimko@gmail.com>
---
 drivers/hwmon/scmi-hwmon.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
index a3b5b5c0ec25..d03174922e65 100644
--- a/drivers/hwmon/scmi-hwmon.c
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -211,8 +211,6 @@ static int scmi_thermal_sensor_register(struct device *dev,
 	tzd = devm_thermal_of_zone_register(dev, th_sensor->info->id, th_sensor,
 					    &scmi_hwmon_thermal_ops);
 	if (IS_ERR(tzd)) {
-		devm_kfree(dev, th_sensor);
-
 		if (PTR_ERR(tzd) != -ENODEV)
 			return PTR_ERR(tzd);
 
-- 
2.43.0

[PATCH v1 3/4] hwmon: scmi: Enhance error reporting with dev_err_probe

[Artyom Shimko]

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

[PATCH v1 0/4] hwmon: scmi: Driver improvements and fixes

[Artyom Shimko]

[-- Attachment #1.1: Type: text/plain, Size: 834 bytes --]

This patch series introduces several improvements to the SCMI HWMON driver:

1. Better handling of unsupported sensor types with debug logging
2. Fixes redundant resource management in thermal registration
3. Enhanced error reporting using dev_err_probe()
4. Added version tracking and proper contributor attribution

The changes maintain backward compatibility while improving:
- Debugging capabilities
- Error reporting clarity
- Code maintenance
- Contributor tracking

Artem Shimko (4):
  hwmon: scmi: Add default case with debug output
  hwmon: scmi: Remove redundant devm_kfree call
  hwmon: scmi: Enhance error reporting with dev_err_probe
  hwmon: scmi: Add driver version and patch author

 drivers/hwmon/scmi-hwmon.c | 50 ++++++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 13 deletions(-)

-- 
2.43.0

[-- Attachment #1.2: Type: text/html, Size: 931 bytes --]

[-- Attachment #2: 0001-hwmon-scmi-Add-default-case-with-debug-output.patch --]
[-- Type: text/x-patch, Size: 1509 bytes --]

From 34ddd8c2117c3fbfba9171f1906341912d135063 Mon Sep 17 00:00:00 2001
From: Artem Shimko <artyom.shimko@gmail.com>
Date: Thu, 31 Jul 2025 16:09:31 +0300
Subject: [PATCH v1 1/4] hwmon: scmi: Add default case with debug output

Improve handling of unsupported sensor types:
- Add default case in sensor type switch statement
- Log skipped sensors with debug information including:
  * Sensor ID
  * Sensor type
  * Sensor name (if available)
- Use rate-limited dev_dbg for safety

Debug output format:
"Skipping unsupported sensor ID:%d Type:%d (%s)"

Signed-off-by: Artem Shimko <artyom.shimko@gmail.com>
---
 drivers/hwmon/scmi-hwmon.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
index 364199b332c0..a3b5b5c0ec25 100644
--- a/drivers/hwmon/scmi-hwmon.c
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -275,6 +275,10 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 			nr_count[type]++;
 			break;
 		}
+		default:
+			dev_dbg(dev, "Skipping unsupported sensor ID:%d Type:%d (%s)\n",
+				i, sensor->type, sensor->name ? sensor->name : "unnamed");
+			continue;
 	}
 
 	if (nr_count[hwmon_temp])
@@ -323,6 +327,10 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 			idx = --nr_count[type];
 			*(scmi_sensors->info[type] + idx) = sensor;
 			break;
+		default:
+			dev_dbg(dev, "Skipping unsupported sensor ID:%d Type:%d (%s)\n",
+				i, sensor->type, sensor->name ? sensor->name : "unnamed");
+			continue;
 		}
 	}
 
-- 
2.43.0


[-- Attachment #3: 0004-hwmon-scmi-Add-driver-version-and-patch-author.patch --]
[-- Type: text/x-patch, Size: 1618 bytes --]

From cbe176fd6280484fcf70ac0b73c370754dc6eed8 Mon Sep 17 00:00:00 2001
From: Artem Shimko <artyom.shimko@gmail.com>
Date: Thu, 31 Jul 2025 16:10:15 +0300
Subject: [PATCH v1 4/4] hwmon: scmi: Add driver version and patch author

Introduce DRIVER_VERSION macro to track driver revisions and add myself
as co-author to the module:
- Define DRIVER_VERSION "1.0" following standard versioning
- Add MODULE_VERSION for in-tree version tracking
- Include my signature as module co-author

This helps with:
- Debugging version-specific issues
- Proper attribution of contributions
- Compatibility checks

Signed-off-by: Artem Shimko <artyom.shimko@gmail.com>
---
 drivers/hwmon/scmi-hwmon.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
index 081502418dfa..6b4b988d63c8 100644
--- a/drivers/hwmon/scmi-hwmon.c
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -4,6 +4,7 @@
  *
  * Copyright (C) 2018-2021 ARM Ltd.
  * Sudeep Holla <sudeep.holla@arm.com>
+ * Patched by Artem Shimko <artyom.shimko@gmail.com>
  */
 
 #include <linux/hwmon.h>
@@ -13,6 +14,8 @@
 #include <linux/sysfs.h>
 #include <linux/thermal.h>
 
+#define DRIVER_VERSION "1.0"
+
 static const struct scmi_sensor_proto_ops *sensor_ops;
 
 struct scmi_sensors {
@@ -389,5 +392,7 @@ static struct scmi_driver scmi_hwmon_drv = {
 module_scmi_driver(scmi_hwmon_drv);
 
 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_AUTHOR("Artem Shimko <artyom.shimko@gmail.com>");
 MODULE_DESCRIPTION("ARM SCMI HWMON interface driver");
 MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DRIVER_VERSION);
-- 
2.43.0


[-- Attachment #4: 0000-cover-letter.patch --]
[-- Type: text/x-patch, Size: 1055 bytes --]

From cbe176fd6280484fcf70ac0b73c370754dc6eed8 Mon Sep 17 00:00:00 2001
From: Artem Shimko <artyom.shimko@gmail.com>
Date: Thu, 31 Jul 2025 16:14:43 +0300
Subject: [PATCH v1 0/4] hwmon: scmi: Driver improvements and fixes

This patch series introduces several improvements to the SCMI HWMON driver:

1. Better handling of unsupported sensor types with debug logging
2. Fixes redundant resource management in thermal registration
3. Enhanced error reporting using dev_err_probe()
4. Added version tracking and proper contributor attribution

The changes maintain backward compatibility while improving:
- Debugging capabilities
- Error reporting clarity
- Code maintenance
- Contributor tracking

Artem Shimko (4):
  hwmon: scmi: Add default case with debug output
  hwmon: scmi: Remove redundant devm_kfree call
  hwmon: scmi: Enhance error reporting with dev_err_probe
  hwmon: scmi: Add driver version and patch author

 drivers/hwmon/scmi-hwmon.c | 50 ++++++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 13 deletions(-)

-- 
2.43.0

[-- Attachment #5: 0002-hwmon-scmi-Remove-redundant-devm_kfree-call.patch --]
[-- Type: text/x-patch, Size: 1175 bytes --]

From 82d9921342af4ca7fb898b215d73642694549fd9 Mon Sep 17 00:00:00 2001
From: Artem Shimko <artyom.shimko@gmail.com>
Date: Thu, 31 Jul 2025 16:10:02 +0300
Subject: [PATCH v1 2/4] hwmon: scmi: Remove redundant devm_kfree call

Fix potential resource management issue by:
- Removing unnecessary devm_kfree() call in error path
- Relying on devres automatic cleanup
- Preserving all error handling logic

Rationale:
- Memory was allocated with devm_kzalloc()
- devm_ thermal registration manages its own resources
- Double-free could occur during probe failure

Signed-off-by: Artem Shimko <artyom.shimko@gmail.com>
---
 drivers/hwmon/scmi-hwmon.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
index a3b5b5c0ec25..d03174922e65 100644
--- a/drivers/hwmon/scmi-hwmon.c
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -211,8 +211,6 @@ static int scmi_thermal_sensor_register(struct device *dev,
 	tzd = devm_thermal_of_zone_register(dev, th_sensor->info->id, th_sensor,
 					    &scmi_hwmon_thermal_ops);
 	if (IS_ERR(tzd)) {
-		devm_kfree(dev, th_sensor);
-
 		if (PTR_ERR(tzd) != -ENODEV)
 			return PTR_ERR(tzd);
 
-- 
2.43.0


[-- Attachment #6: 0003-hwmon-scmi-Enhance-error-reporting-with-dev_err_prob.patch --]
[-- Type: text/x-patch, Size: 4035 bytes --]

From dfa4c25ba0f4ce86d7082f078416a102a7ff91a1 Mon Sep 17 00:00:00 2001
From: Artem Shimko <artyom.shimko@gmail.com>
Date: Thu, 31 Jul 2025 16:10:10 +0300
Subject: [PATCH v1 3/4] hwmon: scmi: Enhance error reporting with
 dev_err_probe

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 v1 0/4] hwmon: scmi: Driver improvements and fixes

[Sudeep Holla]

On Thu, Jul 31, 2025 at 04:21:34PM +0300, Artyom Shimko wrote:
> This patch series introduces several improvements to the SCMI HWMON driver:
> 
> 1. Better handling of unsupported sensor types with debug logging
> 2. Fixes redundant resource management in thermal registration
> 3. Enhanced error reporting using dev_err_probe()
> 4. Added version tracking and proper contributor attribution
> 
> The changes maintain backward compatibility while improving:
> - Debugging capabilities
> - Error reporting clarity
> - Code maintenance
> - Contributor tracking
>

Thanks for the patches. Please read section
"No MIME, no links, no compression, no attachments.  Just plain text"
in Documentation/process/submitting-patches.rst

I see your patches as attachments which is not correct way to send the
patches. Fix the same and resend it properly with each patch as separate
email threaded to the cover letter.

-- 
Regards,
Sudeep