Adds lwmi_is_attr_01_supported, and only creates the attribute subfolder
if the attribute is supported by the hardware. Due to some poorly
implemented BIOS, this is a multi-step sequence of events. This is
because:
- Some BIOS support getting the capability data from custom mode (0xff),
  while others only support it in no-mode (0x00).
- Similarly, some BIOS support get/set for the current value from custom
  mode (0xff), while others only support it in no-mode (0x00).
- Some BIOS report capability data for a method that is not fully
  implemented.
- Some BIOS have methods fully implemented, but no complimentary
  capability data.

To ensure we only expose fully implemented methods with corresponding
capability data, we check each outcome before reporting that an
attribute can be supported.

Checking for lwmi_is_attr_01_supported during remove is not done to
ensure that we don't attempt to call cd01 or send WMI events if one of
the interfaces being removed was the cause of the driver unloading.

While adding members to tunable_attr_01, remove unused capdata pointer
and limit size of all ID's to the appropriate size.

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reported-by: Kurt Borja <kuurtb@gmail.com>
Closes: https://lore.kernel.org/platform-driver-x86/DG60P3SHXR8H.3NSEHMZ6J7XRC@gmail.com/
Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
---
 drivers/platform/x86/lenovo/wmi-other.c | 117 +++++++++++++++++++++---
 1 file changed, 102 insertions(+), 15 deletions(-)

diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
index 95886df39c8d..f3f12303e379 100644
--- a/drivers/platform/x86/lenovo/wmi-other.c
+++ b/drivers/platform/x86/lenovo/wmi-other.c
@@ -545,11 +545,12 @@ static void lwmi_om_fan_info_collect_cd_fan(struct device *dev, struct cd_list *
 /* ======== fw_attributes (component: lenovo-wmi-capdata 01) ======== */
 
 struct tunable_attr_01 {
-	struct capdata01 *capdata;
 	struct device *dev;
-	u32 feature_id;
-	u32 device_id;
-	u32 type_id;
+	u8 feature_id;
+	u8 device_id;
+	u8 type_id;
+	u8 cd_mode_id; /* mode arg for searching capdata */
+	u8 cv_mode_id; /* mode arg for set/get current_value */
 };
 
 static struct tunable_attr_01 ppt_pl1_spl = {
@@ -716,7 +717,7 @@ static ssize_t attr_capdata01_show(struct kobject *kobj,
 	int value, ret;
 
 	attribute_id = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
-				    LWMI_GZ_THERMAL_MODE_CUSTOM, tunable_attr->type_id);
+				    tunable_attr->cd_mode_id, tunable_attr->type_id);
 
 	ret = lwmi_cd01_get_data(priv->cd01_list, attribute_id, &capdata);
 	if (ret)
@@ -782,7 +783,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
 		return -EBUSY;
 
 	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
-				 mode, tunable_attr->type_id);
+				 tunable_attr->cd_mode_id, tunable_attr->type_id);
 
 	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
 	if (ret)
@@ -795,6 +796,8 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
 	if (value < capdata.min_value || value > capdata.max_value)
 		return -EINVAL;
 
+	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
+				 tunable_attr->cv_mode_id, tunable_attr->type_id);
 	args.arg1 = value;
 
 	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_SET,
@@ -828,13 +831,16 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
 	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
 	struct wmi_method_args_32 args;
 	enum thermal_mode mode;
-	int retval;
-	int ret;
+	int retval, ret;
 
 	ret = lwmi_om_notifier_call(&mode);
 	if (ret)
 		return ret;
 
+	/* If "no-mode" is the supported mode, ensure we never send current mode */
+	if (tunable_attr->cv_mode_id == LWMI_GZ_THERMAL_MODE_NONE)
+		mode = tunable_attr->cv_mode_id;
+
 	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
 				 mode, tunable_attr->type_id);
 
@@ -847,6 +853,85 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
 	return sysfs_emit(buf, "%d\n", retval);
 }
 
+/**
+ * lwmi_attr_01_is_supported() - Determine if the given attribute is supported.
+ * @tunable_attr: The attribute to verify.
+ *
+ * First check if the attribute has a corresponding capdata01 table in the cd01
+ * module under the "custom" mode (0xff). If that is not present then check if
+ * there is a corresponding "no-mode" (0x00) entry. If either of those passes,
+ * check capdata->supported for values > 0. If capdata is available, attempt to
+ * determine the set/get mode for the current value property using a similar
+ * pattern. If the value returned by either custom or no-mode is 0, or we get
+ * an error, we assume that mode is not supported. If any of the above checks
+ * fail then the attribute is not fully supported.
+ *
+ * The probed cd_mode_id/cv_mode_id are stored on the tunable_attr for later
+ * reference.
+ *
+ * Return: Support level, or an error code.
+ */
+static int lwmi_attr_01_is_supported(struct tunable_attr_01 *tunable_attr)
+{
+	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
+	u8 mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
+	struct wmi_method_args_32 args;
+	struct capdata01 capdata;
+	int retval, ret;
+
+	/* Determine tunable_attr->cd_mode_id */
+no_mode_fallback_1:
+	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
+				 mode, tunable_attr->type_id);
+
+	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
+	if (ret && mode) {
+		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
+		mode = LWMI_GZ_THERMAL_MODE_NONE;
+		goto no_mode_fallback_1;
+	}
+	if (ret)
+		goto not_supported;
+	if (!capdata.supported) {
+		ret = -EOPNOTSUPP;
+		goto not_supported;
+	}
+
+	tunable_attr->cd_mode_id = mode;
+
+	/* Determine tunable_attr->cv_mode_id */
+	mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
+no_mode_fallback_2:
+	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
+				 mode, tunable_attr->type_id);
+
+	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET,
+				    (unsigned char *)&args, sizeof(args),
+				    &retval);
+	if ((ret && mode) || (!retval && mode)) {
+		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
+		mode = LWMI_GZ_THERMAL_MODE_NONE;
+		goto no_mode_fallback_2;
+	}
+	if (ret)
+		goto not_supported;
+	if (retval == 0) {
+		ret = -EOPNOTSUPP;
+		goto not_supported;
+	}
+
+	tunable_attr->cv_mode_id = mode;
+	dev_dbg(tunable_attr->dev, "cd_mode_id: %02x%02x%02x%02x, cv_mode_id: %#08x attribute support level: %x\n",
+		tunable_attr->device_id, tunable_attr->feature_id, tunable_attr->cd_mode_id,
+		tunable_attr->type_id, args.arg0, capdata.supported);
+
+	return capdata.supported;
+
+not_supported:
+	dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
+	return ret;
+}
+
 /* Lenovo WMI Other Mode Attribute macros */
 #define __LWMI_ATTR_RO(_func, _name)                                  \
 	{                                                             \
@@ -970,19 +1055,21 @@ static int lwmi_om_fw_attr_add(struct lwmi_om_priv *priv)
 	}
 
 	for (i = 0; i < ARRAY_SIZE(cd01_attr_groups) - 1; i++) {
-		err = sysfs_create_group(&priv->fw_attr_kset->kobj,
-					 cd01_attr_groups[i].attr_group);
-		if (err)
-			goto err_remove_groups;
-
 		cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev;
+		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0) {
+			err = sysfs_create_group(&priv->fw_attr_kset->kobj,
+						 cd01_attr_groups[i].attr_group);
+			if (err)
+				goto err_remove_groups;
+		}
 	}
 	return 0;
 
 err_remove_groups:
 	while (i--)
-		sysfs_remove_group(&priv->fw_attr_kset->kobj,
-				   cd01_attr_groups[i].attr_group);
+		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0)
+			sysfs_remove_group(&priv->fw_attr_kset->kobj,
+					   cd01_attr_groups[i].attr_group);
 
 	kset_unregister(priv->fw_attr_kset);
 
-- 
2.52.0

Hi Derek,

On Tue, 2026-02-24 at 04:31 +0000, Derek J. Clark wrote:
> Adds lwmi_is_attr_01_supported, and only creates the attribute subfolder
> if the attribute is supported by the hardware. Due to some poorly
> implemented BIOS, this is a multi-step sequence of events. This is
> because:
> - Some BIOS support getting the capability data from custom mode (0xff),
>   while others only support it in no-mode (0x00).
> - Similarly, some BIOS support get/set for the current value from custom
>   mode (0xff), while others only support it in no-mode (0x00).
> - Some BIOS report capability data for a method that is not fully
>   implemented.
> - Some BIOS have methods fully implemented, but no complimentary
>   capability data.
> 
> To ensure we only expose fully implemented methods with corresponding
> capability data, we check each outcome before reporting that an
> attribute can be supported.
> 
> Checking for lwmi_is_attr_01_supported during remove is not done to
> ensure that we don't attempt to call cd01 or send WMI events if one of
> the interfaces being removed was the cause of the driver unloading.
> 
> While adding members to tunable_attr_01, remove unused capdata pointer
> and limit size of all ID's to the appropriate size.
> 
> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> Reported-by: Kurt Borja <kuurtb@gmail.com>
> Closes: https://lore.kernel.org/platform-driver-x86/DG60P3SHXR8H.3NSEHMZ6J7XRC@gmail.com/
> Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
> ---
>  drivers/platform/x86/lenovo/wmi-other.c | 117 +++++++++++++++++++++---
>  1 file changed, 102 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> index 95886df39c8d..f3f12303e379 100644
> --- a/drivers/platform/x86/lenovo/wmi-other.c
> +++ b/drivers/platform/x86/lenovo/wmi-other.c
> @@ -545,11 +545,12 @@ static void lwmi_om_fan_info_collect_cd_fan(struct device *dev, struct cd_list *
>  /* ======== fw_attributes (component: lenovo-wmi-capdata 01) ======== */
>  
>  struct tunable_attr_01 {
> -	struct capdata01 *capdata;
>  	struct device *dev;
> -	u32 feature_id;
> -	u32 device_id;
> -	u32 type_id;
> +	u8 feature_id;
> +	u8 device_id;
> +	u8 type_id;
> +	u8 cd_mode_id; /* mode arg for searching capdata */
> +	u8 cv_mode_id; /* mode arg for set/get current_value */
>  };
>  
>  static struct tunable_attr_01 ppt_pl1_spl = {
> @@ -716,7 +717,7 @@ static ssize_t attr_capdata01_show(struct kobject *kobj,
>  	int value, ret;
>  
>  	attribute_id = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> -				    LWMI_GZ_THERMAL_MODE_CUSTOM, tunable_attr->type_id);
> +				    tunable_attr->cd_mode_id, tunable_attr->type_id);
>  
>  	ret = lwmi_cd01_get_data(priv->cd01_list, attribute_id, &capdata);
>  	if (ret)
> @@ -782,7 +783,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
>  		return -EBUSY;
>  
>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> -				 mode, tunable_attr->type_id);
> +				 tunable_attr->cd_mode_id, tunable_attr->type_id);
>  
>  	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
>  	if (ret)
> @@ -795,6 +796,8 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
>  	if (value < capdata.min_value || value > capdata.max_value)
>  		return -EINVAL;
>  
> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> +				 tunable_attr->cv_mode_id, tunable_attr->type_id);
>  	args.arg1 = value;
>  
>  	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_SET,
> @@ -828,13 +831,16 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
>  	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
>  	struct wmi_method_args_32 args;
>  	enum thermal_mode mode;
> -	int retval;
> -	int ret;
> +	int retval, ret;
>  
>  	ret = lwmi_om_notifier_call(&mode);
>  	if (ret)
>  		return ret;
>  
> +	/* If "no-mode" is the supported mode, ensure we never send current mode */
> +	if (tunable_attr->cv_mode_id == LWMI_GZ_THERMAL_MODE_NONE)
> +		mode = tunable_attr->cv_mode_id;
> +
>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>  				 mode, tunable_attr->type_id);
>  
> @@ -847,6 +853,85 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
>  	return sysfs_emit(buf, "%d\n", retval);
>  }
>  
> +/**
> + * lwmi_attr_01_is_supported() - Determine if the given attribute is supported.
> + * @tunable_attr: The attribute to verify.
> + *
> + * First check if the attribute has a corresponding capdata01 table in the cd01
> + * module under the "custom" mode (0xff). If that is not present then check if
> + * there is a corresponding "no-mode" (0x00) entry. If either of those passes,
> + * check capdata->supported for values > 0. If capdata is available, attempt to
> + * determine the set/get mode for the current value property using a similar
> + * pattern. If the value returned by either custom or no-mode is 0, or we get
> + * an error, we assume that mode is not supported. If any of the above checks
> + * fail then the attribute is not fully supported.
> + *
> + * The probed cd_mode_id/cv_mode_id are stored on the tunable_attr for later
> + * reference.
> + *
> + * Return: Support level, or an error code.
> + */
> +static int lwmi_attr_01_is_supported(struct tunable_attr_01 *tunable_attr)
> +{
> +	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
> +	u8 mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
> +	struct wmi_method_args_32 args;
> +	struct capdata01 capdata;
> +	int retval, ret;
> +
> +	/* Determine tunable_attr->cd_mode_id */
> +no_mode_fallback_1:
> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> +				 mode, tunable_attr->type_id);
> +
> +	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
> +	if (ret && mode) {
> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
> +		goto no_mode_fallback_1;
> +	}
> +	if (ret)
> +		goto not_supported;
> +	if (!capdata.supported) {
> +		ret = -EOPNOTSUPP;
> +		goto not_supported;
> +	}
> +
> +	tunable_attr->cd_mode_id = mode;
> +
> +	/* Determine tunable_attr->cv_mode_id */
> +	mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
> +no_mode_fallback_2:
> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> +				 mode, tunable_attr->type_id);
> +
> +	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET,
> +				    (unsigned char *)&args, sizeof(args),
> +				    &retval);
> +	if ((ret && mode) || (!retval && mode)) {
> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
> +		goto no_mode_fallback_2;
> +	}
> +	if (ret)
> +		goto not_supported;
> +	if (retval == 0) {
> +		ret = -EOPNOTSUPP;
> +		goto not_supported;
> +	}
> +

I agree with Ilpo that backward gotos are hard to read and should be
avoided if possible.

> +	tunable_attr->cv_mode_id = mode;
> +	dev_dbg(tunable_attr->dev, "cd_mode_id: %02x%02x%02x%02x, cv_mode_id: %#08x attribute support level: %x\n",

It's a long line. Wrap at the first comma?

> +		tunable_attr->device_id, tunable_attr->feature_id, tunable_attr->cd_mode_id,
> +		tunable_attr->type_id, args.arg0, capdata.supported);
> +
> +	return capdata.supported;
> +
> +not_supported:
> +	dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> +	return ret;
> +}
> +
>  /* Lenovo WMI Other Mode Attribute macros */
>  #define __LWMI_ATTR_RO(_func, _name)                                  \
>  	{                                                             \
> @@ -970,19 +1055,21 @@ static int lwmi_om_fw_attr_add(struct lwmi_om_priv *priv)
>  	}
>  
>  	for (i = 0; i < ARRAY_SIZE(cd01_attr_groups) - 1; i++) {
> -		err = sysfs_create_group(&priv->fw_attr_kset->kobj,
> -					 cd01_attr_groups[i].attr_group);
> -		if (err)
> -			goto err_remove_groups;
> -
>  		cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev;
> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0) {
> +			err = sysfs_create_group(&priv->fw_attr_kset->kobj,
> +						 cd01_attr_groups[i].attr_group);
> +			if (err)
> +				goto err_remove_groups;
> +		}
>  	}
>  	return 0;
>  
>  err_remove_groups:
>  	while (i--)
> -		sysfs_remove_group(&priv->fw_attr_kset->kobj,
> -				   cd01_attr_groups[i].attr_group);
> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0)

I don't see lwmi_om_fw_attr_remove() doing the same. If we care about
symmetric cleanup, I would imagine a bitmap or so recording what have
been created is used there.

Also it's doubtful if the firmware always return the same result on the
same parameters. If a broken firmware somehow returns different results
here, some attributes may be left uncleaned.

That being said, I am not sure if we really need symmetric cleanup.
IIUC, sysfs_remove_group() is a no-op if we pass an attr_group that has
not been created.

> +			sysfs_remove_group(&priv->fw_attr_kset->kobj,
> +					   cd01_attr_groups[i].attr_group);
>  
>  	kset_unregister(priv->fw_attr_kset);
>  

Thanks,
Rong

On February 25, 2026 9:14:12 AM PST, Rong Zhang <i@rong.moe> wrote:
>Hi Derek,
>
>On Tue, 2026-02-24 at 04:31 +0000, Derek J. Clark wrote:
>> Adds lwmi_is_attr_01_supported, and only creates the attribute subfolder
>> if the attribute is supported by the hardware. Due to some poorly
>> implemented BIOS, this is a multi-step sequence of events. This is
>> because:
>> - Some BIOS support getting the capability data from custom mode (0xff),
>>   while others only support it in no-mode (0x00).
>> - Similarly, some BIOS support get/set for the current value from custom
>>   mode (0xff), while others only support it in no-mode (0x00).
>> - Some BIOS report capability data for a method that is not fully
>>   implemented.
>> - Some BIOS have methods fully implemented, but no complimentary
>>   capability data.
>> 
>> To ensure we only expose fully implemented methods with corresponding
>> capability data, we check each outcome before reporting that an
>> attribute can be supported.
>> 
>> Checking for lwmi_is_attr_01_supported during remove is not done to
>> ensure that we don't attempt to call cd01 or send WMI events if one of
>> the interfaces being removed was the cause of the driver unloading.
>> 
>> While adding members to tunable_attr_01, remove unused capdata pointer
>> and limit size of all ID's to the appropriate size.
>> 
>> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
>> Reported-by: Kurt Borja <kuurtb@gmail.com>
>> Closes: https://lore.kernel.org/platform-driver-x86/DG60P3SHXR8H.3NSEHMZ6J7XRC@gmail.com/
>> Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
>> ---
>>  drivers/platform/x86/lenovo/wmi-other.c | 117 +++++++++++++++++++++---
>>  1 file changed, 102 insertions(+), 15 deletions(-)
>> 
>> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
>> index 95886df39c8d..f3f12303e379 100644
>> --- a/drivers/platform/x86/lenovo/wmi-other.c
>> +++ b/drivers/platform/x86/lenovo/wmi-other.c
>> @@ -545,11 +545,12 @@ static void lwmi_om_fan_info_collect_cd_fan(struct device *dev, struct cd_list *
>>  /* ======== fw_attributes (component: lenovo-wmi-capdata 01) ======== */
>>  
>>  struct tunable_attr_01 {
>> -	struct capdata01 *capdata;
>>  	struct device *dev;
>> -	u32 feature_id;
>> -	u32 device_id;
>> -	u32 type_id;
>> +	u8 feature_id;
>> +	u8 device_id;
>> +	u8 type_id;
>> +	u8 cd_mode_id; /* mode arg for searching capdata */
>> +	u8 cv_mode_id; /* mode arg for set/get current_value */
>>  };
>>  
>>  static struct tunable_attr_01 ppt_pl1_spl = {
>> @@ -716,7 +717,7 @@ static ssize_t attr_capdata01_show(struct kobject *kobj,
>>  	int value, ret;
>>  
>>  	attribute_id = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> -				    LWMI_GZ_THERMAL_MODE_CUSTOM, tunable_attr->type_id);
>> +				    tunable_attr->cd_mode_id, tunable_attr->type_id);
>>  
>>  	ret = lwmi_cd01_get_data(priv->cd01_list, attribute_id, &capdata);
>>  	if (ret)
>> @@ -782,7 +783,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
>>  		return -EBUSY;
>>  
>>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> -				 mode, tunable_attr->type_id);
>> +				 tunable_attr->cd_mode_id, tunable_attr->type_id);
>>  
>>  	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
>>  	if (ret)
>> @@ -795,6 +796,8 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
>>  	if (value < capdata.min_value || value > capdata.max_value)
>>  		return -EINVAL;
>>  
>> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> +				 tunable_attr->cv_mode_id, tunable_attr->type_id);
>>  	args.arg1 = value;
>>  
>>  	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_SET,
>> @@ -828,13 +831,16 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
>>  	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
>>  	struct wmi_method_args_32 args;
>>  	enum thermal_mode mode;
>> -	int retval;
>> -	int ret;
>> +	int retval, ret;
>>  
>>  	ret = lwmi_om_notifier_call(&mode);
>>  	if (ret)
>>  		return ret;
>>  
>> +	/* If "no-mode" is the supported mode, ensure we never send current mode */
>> +	if (tunable_attr->cv_mode_id == LWMI_GZ_THERMAL_MODE_NONE)
>> +		mode = tunable_attr->cv_mode_id;
>> +
>>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>>  				 mode, tunable_attr->type_id);
>>  
>> @@ -847,6 +853,85 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
>>  	return sysfs_emit(buf, "%d\n", retval);
>>  }
>>  
>> +/**
>> + * lwmi_attr_01_is_supported() - Determine if the given attribute is supported.
>> + * @tunable_attr: The attribute to verify.
>> + *
>> + * First check if the attribute has a corresponding capdata01 table in the cd01
>> + * module under the "custom" mode (0xff). If that is not present then check if
>> + * there is a corresponding "no-mode" (0x00) entry. If either of those passes,
>> + * check capdata->supported for values > 0. If capdata is available, attempt to
>> + * determine the set/get mode for the current value property using a similar
>> + * pattern. If the value returned by either custom or no-mode is 0, or we get
>> + * an error, we assume that mode is not supported. If any of the above checks
>> + * fail then the attribute is not fully supported.
>> + *
>> + * The probed cd_mode_id/cv_mode_id are stored on the tunable_attr for later
>> + * reference.
>> + *
>> + * Return: Support level, or an error code.
>> + */
>> +static int lwmi_attr_01_is_supported(struct tunable_attr_01 *tunable_attr)
>> +{
>> +	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
>> +	u8 mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
>> +	struct wmi_method_args_32 args;
>> +	struct capdata01 capdata;
>> +	int retval, ret;
>> +
>> +	/* Determine tunable_attr->cd_mode_id */
>> +no_mode_fallback_1:
>> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> +				 mode, tunable_attr->type_id);
>> +
>> +	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
>> +	if (ret && mode) {
>> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
>> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
>> +		goto no_mode_fallback_1;
>> +	}
>> +	if (ret)
>> +		goto not_supported;
>> +	if (!capdata.supported) {
>> +		ret = -EOPNOTSUPP;
>> +		goto not_supported;
>> +	}
>> +
>> +	tunable_attr->cd_mode_id = mode;
>> +
>> +	/* Determine tunable_attr->cv_mode_id */
>> +	mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
>> +no_mode_fallback_2:
>> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> +				 mode, tunable_attr->type_id);
>> +
>> +	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET,
>> +				    (unsigned char *)&args, sizeof(args),
>> +				    &retval);
>> +	if ((ret && mode) || (!retval && mode)) {
>> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
>> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
>> +		goto no_mode_fallback_2;
>> +	}
>> +	if (ret)
>> +		goto not_supported;
>> +	if (retval == 0) {
>> +		ret = -EOPNOTSUPP;
>> +		goto not_supported;
>> +	}
>> +
>
>I agree with Ilpo that backward gotos are hard to read and should be
>avoided if possible.
>
>> +	tunable_attr->cv_mode_id = mode;
>> +	dev_dbg(tunable_attr->dev, "cd_mode_id: %02x%02x%02x%02x, cv_mode_id: %#08x attribute support level: %x\n",
>
>It's a long line. Wrap at the first comma?
>
>> +		tunable_attr->device_id, tunable_attr->feature_id, tunable_attr->cd_mode_id,
>> +		tunable_attr->type_id, args.arg0, capdata.supported);
>> +
>> +	return capdata.supported;
>> +
>> +not_supported:
>> +	dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
>> +	return ret;
>> +}
>> +
>>  /* Lenovo WMI Other Mode Attribute macros */
>>  #define __LWMI_ATTR_RO(_func, _name)                                  \
>>  	{                                                             \
>> @@ -970,19 +1055,21 @@ static int lwmi_om_fw_attr_add(struct lwmi_om_priv *priv)
>>  	}
>>  
>>  	for (i = 0; i < ARRAY_SIZE(cd01_attr_groups) - 1; i++) {
>> -		err = sysfs_create_group(&priv->fw_attr_kset->kobj,
>> -					 cd01_attr_groups[i].attr_group);
>> -		if (err)
>> -			goto err_remove_groups;
>> -
>>  		cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev;
>> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0) {
>> +			err = sysfs_create_group(&priv->fw_attr_kset->kobj,
>> +						 cd01_attr_groups[i].attr_group);
>> +			if (err)
>> +				goto err_remove_groups;
>> +		}
>>  	}
>>  	return 0;
>>  
>>  err_remove_groups:
>>  	while (i--)
>> -		sysfs_remove_group(&priv->fw_attr_kset->kobj,
>> -				   cd01_attr_groups[i].attr_group);
>> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0)
>
>I don't see lwmi_om_fw_attr_remove() doing the same. If we care about
>symmetric cleanup, I would imagine a bitmap or so recording what have
>been created is used there.
>
>Also it's doubtful if the firmware always return the same result on the
>same parameters. If a broken firmware somehow returns different results
>here, some attributes may be left uncleaned.
>
>That being said, I am not sure if we really need symmetric cleanup.
>IIUC, sysfs_remove_group() is a no-op if we pass an attr_group that has
>not been created.

Hi Rong,
We don't want to query the interface if it was removed, and the no-op is harmless. It doesn't seem worth it to me to retain that in memory to achieve the same results.

>> +			sysfs_remove_group(&priv->fw_attr_kset->kobj,
>> +					   cd01_attr_groups[i].attr_group);
>>  
>>  	kset_unregister(priv->fw_attr_kset);
>>  
>
>Thanks,
>Rong

Hi Derek,

On Wed, 2026-02-25 at 10:09 -0800, Derek J. Clark wrote:
> On February 25, 2026 9:14:12 AM PST, Rong Zhang <i@rong.moe> wrote:
> > Hi Derek,
> > 
> > On Tue, 2026-02-24 at 04:31 +0000, Derek J. Clark wrote:
> > > Adds lwmi_is_attr_01_supported, and only creates the attribute subfolder
> > > if the attribute is supported by the hardware. Due to some poorly
> > > implemented BIOS, this is a multi-step sequence of events. This is
> > > because:
> > > - Some BIOS support getting the capability data from custom mode (0xff),
> > >   while others only support it in no-mode (0x00).
> > > - Similarly, some BIOS support get/set for the current value from custom
> > >   mode (0xff), while others only support it in no-mode (0x00).
> > > - Some BIOS report capability data for a method that is not fully
> > >   implemented.
> > > - Some BIOS have methods fully implemented, but no complimentary
> > >   capability data.
> > > 
> > > To ensure we only expose fully implemented methods with corresponding
> > > capability data, we check each outcome before reporting that an
> > > attribute can be supported.
> > > 
> > > Checking for lwmi_is_attr_01_supported during remove is not done to
> > > ensure that we don't attempt to call cd01 or send WMI events if one of
> > > the interfaces being removed was the cause of the driver unloading.
> > > 
> > > While adding members to tunable_attr_01, remove unused capdata pointer
> > > and limit size of all ID's to the appropriate size.
> > > 
> > > Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> > > Reported-by: Kurt Borja <kuurtb@gmail.com>
> > > Closes: https://lore.kernel.org/platform-driver-x86/DG60P3SHXR8H.3NSEHMZ6J7XRC@gmail.com/
> > > Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
> > > ---
> > >  drivers/platform/x86/lenovo/wmi-other.c | 117 +++++++++++++++++++++---
> > >  1 file changed, 102 insertions(+), 15 deletions(-)
> > > 
> > > diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> > > index 95886df39c8d..f3f12303e379 100644
> > > --- a/drivers/platform/x86/lenovo/wmi-other.c
> > > +++ b/drivers/platform/x86/lenovo/wmi-other.c
> > > @@ -545,11 +545,12 @@ static void lwmi_om_fan_info_collect_cd_fan(struct device *dev, struct cd_list *
> > >  /* ======== fw_attributes (component: lenovo-wmi-capdata 01) ======== */
> > >  
> > >  struct tunable_attr_01 {
> > > -	struct capdata01 *capdata;
> > >  	struct device *dev;
> > > -	u32 feature_id;
> > > -	u32 device_id;
> > > -	u32 type_id;
> > > +	u8 feature_id;
> > > +	u8 device_id;
> > > +	u8 type_id;
> > > +	u8 cd_mode_id; /* mode arg for searching capdata */
> > > +	u8 cv_mode_id; /* mode arg for set/get current_value */
> > >  };
> > >  
> > >  static struct tunable_attr_01 ppt_pl1_spl = {
> > > @@ -716,7 +717,7 @@ static ssize_t attr_capdata01_show(struct kobject *kobj,
> > >  	int value, ret;
> > >  
> > >  	attribute_id = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> > > -				    LWMI_GZ_THERMAL_MODE_CUSTOM, tunable_attr->type_id);
> > > +				    tunable_attr->cd_mode_id, tunable_attr->type_id);
> > >  
> > >  	ret = lwmi_cd01_get_data(priv->cd01_list, attribute_id, &capdata);
> > >  	if (ret)
> > > @@ -782,7 +783,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
> > >  		return -EBUSY;
> > >  
> > >  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> > > -				 mode, tunable_attr->type_id);
> > > +				 tunable_attr->cd_mode_id, tunable_attr->type_id);
> > >  
> > >  	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
> > >  	if (ret)
> > > @@ -795,6 +796,8 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
> > >  	if (value < capdata.min_value || value > capdata.max_value)
> > >  		return -EINVAL;
> > >  
> > > +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> > > +				 tunable_attr->cv_mode_id, tunable_attr->type_id);
> > >  	args.arg1 = value;
> > >  
> > >  	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_SET,
> > > @@ -828,13 +831,16 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
> > >  	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
> > >  	struct wmi_method_args_32 args;
> > >  	enum thermal_mode mode;
> > > -	int retval;
> > > -	int ret;
> > > +	int retval, ret;
> > >  
> > >  	ret = lwmi_om_notifier_call(&mode);
> > >  	if (ret)
> > >  		return ret;
> > >  
> > > +	/* If "no-mode" is the supported mode, ensure we never send current mode */
> > > +	if (tunable_attr->cv_mode_id == LWMI_GZ_THERMAL_MODE_NONE)
> > > +		mode = tunable_attr->cv_mode_id;
> > > +
> > >  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> > >  				 mode, tunable_attr->type_id);
> > >  
> > > @@ -847,6 +853,85 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
> > >  	return sysfs_emit(buf, "%d\n", retval);
> > >  }
> > >  
> > > +/**
> > > + * lwmi_attr_01_is_supported() - Determine if the given attribute is supported.
> > > + * @tunable_attr: The attribute to verify.
> > > + *
> > > + * First check if the attribute has a corresponding capdata01 table in the cd01
> > > + * module under the "custom" mode (0xff). If that is not present then check if
> > > + * there is a corresponding "no-mode" (0x00) entry. If either of those passes,
> > > + * check capdata->supported for values > 0. If capdata is available, attempt to
> > > + * determine the set/get mode for the current value property using a similar
> > > + * pattern. If the value returned by either custom or no-mode is 0, or we get
> > > + * an error, we assume that mode is not supported. If any of the above checks
> > > + * fail then the attribute is not fully supported.
> > > + *
> > > + * The probed cd_mode_id/cv_mode_id are stored on the tunable_attr for later
> > > + * reference.
> > > + *
> > > + * Return: Support level, or an error code.
> > > + */
> > > +static int lwmi_attr_01_is_supported(struct tunable_attr_01 *tunable_attr)
> > > +{
> > > +	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
> > > +	u8 mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
> > > +	struct wmi_method_args_32 args;
> > > +	struct capdata01 capdata;
> > > +	int retval, ret;
> > > +
> > > +	/* Determine tunable_attr->cd_mode_id */
> > > +no_mode_fallback_1:
> > > +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> > > +				 mode, tunable_attr->type_id);
> > > +
> > > +	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
> > > +	if (ret && mode) {
> > > +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> > > +		mode = LWMI_GZ_THERMAL_MODE_NONE;
> > > +		goto no_mode_fallback_1;
> > > +	}
> > > +	if (ret)
> > > +		goto not_supported;
> > > +	if (!capdata.supported) {
> > > +		ret = -EOPNOTSUPP;
> > > +		goto not_supported;
> > > +	}
> > > +
> > > +	tunable_attr->cd_mode_id = mode;
> > > +
> > > +	/* Determine tunable_attr->cv_mode_id */
> > > +	mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
> > > +no_mode_fallback_2:
> > > +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> > > +				 mode, tunable_attr->type_id);
> > > +
> > > +	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET,
> > > +				    (unsigned char *)&args, sizeof(args),
> > > +				    &retval);
> > > +	if ((ret && mode) || (!retval && mode)) {
> > > +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> > > +		mode = LWMI_GZ_THERMAL_MODE_NONE;
> > > +		goto no_mode_fallback_2;
> > > +	}
> > > +	if (ret)
> > > +		goto not_supported;
> > > +	if (retval == 0) {
> > > +		ret = -EOPNOTSUPP;
> > > +		goto not_supported;
> > > +	}
> > > +
> > 
> > I agree with Ilpo that backward gotos are hard to read and should be
> > avoided if possible.
> > 
> > > +	tunable_attr->cv_mode_id = mode;
> > > +	dev_dbg(tunable_attr->dev, "cd_mode_id: %02x%02x%02x%02x, cv_mode_id: %#08x attribute support level: %x\n",
> > 
> > It's a long line. Wrap at the first comma?
> > 
> > > +		tunable_attr->device_id, tunable_attr->feature_id, tunable_attr->cd_mode_id,
> > > +		tunable_attr->type_id, args.arg0, capdata.supported);
> > > +
> > > +	return capdata.supported;
> > > +
> > > +not_supported:
> > > +	dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> > > +	return ret;
> > > +}
> > > +
> > >  /* Lenovo WMI Other Mode Attribute macros */
> > >  #define __LWMI_ATTR_RO(_func, _name)                                  \
> > >  	{                                                             \
> > > @@ -970,19 +1055,21 @@ static int lwmi_om_fw_attr_add(struct lwmi_om_priv *priv)
> > >  	}
> > >  
> > >  	for (i = 0; i < ARRAY_SIZE(cd01_attr_groups) - 1; i++) {
> > > -		err = sysfs_create_group(&priv->fw_attr_kset->kobj,
> > > -					 cd01_attr_groups[i].attr_group);
> > > -		if (err)
> > > -			goto err_remove_groups;
> > > -
> > >  		cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev;
> > > +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0) {
> > > +			err = sysfs_create_group(&priv->fw_attr_kset->kobj,
> > > +						 cd01_attr_groups[i].attr_group);
> > > +			if (err)
> > > +				goto err_remove_groups;
> > > +		}
> > >  	}
> > >  	return 0;
> > >  
> > >  err_remove_groups:
> > >  	while (i--)
> > > -		sysfs_remove_group(&priv->fw_attr_kset->kobj,
> > > -				   cd01_attr_groups[i].attr_group);
> > > +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0)
> > 
> > I don't see lwmi_om_fw_attr_remove() doing the same. If we care about
> > symmetric cleanup, I would imagine a bitmap or so recording what have
> > been created is used there.
> > 
> > Also it's doubtful if the firmware always return the same result on the
> > same parameters. If a broken firmware somehow returns different results
> > here, some attributes may be left uncleaned.
> > 
> > That being said, I am not sure if we really need symmetric cleanup.
> > IIUC, sysfs_remove_group() is a no-op if we pass an attr_group that has
> > not been created.
> 
> Hi Rong,
> We don't want to query the interface if it was removed, and the no-op is harmless. It doesn't seem worth it to me to retain that in memory to achieve the same results.

Makes sense. Then I would suggest drop the lwmi_attr_01_is_supported()
check here so that we don't need to worry about broken firmware.

Thanks,
Rong

> > > +			sysfs_remove_group(&priv->fw_attr_kset->kobj,
> > > +					   cd01_attr_groups[i].attr_group);
> > >  
> > >  	kset_unregister(priv->fw_attr_kset);
> > >  
> > 
> > Thanks,
> > Rong

On Tue, 24 Feb 2026, Derek J. Clark wrote:

> Adds lwmi_is_attr_01_supported, and only creates the attribute subfolder
> if the attribute is supported by the hardware. Due to some poorly
> implemented BIOS, this is a multi-step sequence of events. This is
> because:
> - Some BIOS support getting the capability data from custom mode (0xff),
>   while others only support it in no-mode (0x00).
> - Similarly, some BIOS support get/set for the current value from custom
>   mode (0xff), while others only support it in no-mode (0x00).
> - Some BIOS report capability data for a method that is not fully
>   implemented.
> - Some BIOS have methods fully implemented, but no complimentary
>   capability data.
> 
> To ensure we only expose fully implemented methods with corresponding
> capability data, we check each outcome before reporting that an
> attribute can be supported.
> 
> Checking for lwmi_is_attr_01_supported during remove is not done to
> ensure that we don't attempt to call cd01 or send WMI events if one of
> the interfaces being removed was the cause of the driver unloading.
> 

> While adding members to tunable_attr_01, remove unused capdata pointer
> and limit size of all ID's to the appropriate size.

Please don't mix changes like this. Create a seprate patch for it.

> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> Reported-by: Kurt Borja <kuurtb@gmail.com>
> Closes: https://lore.kernel.org/platform-driver-x86/DG60P3SHXR8H.3NSEHMZ6J7XRC@gmail.com/
> Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
> ---
>  drivers/platform/x86/lenovo/wmi-other.c | 117 +++++++++++++++++++++---
>  1 file changed, 102 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> index 95886df39c8d..f3f12303e379 100644
> --- a/drivers/platform/x86/lenovo/wmi-other.c
> +++ b/drivers/platform/x86/lenovo/wmi-other.c
> @@ -545,11 +545,12 @@ static void lwmi_om_fan_info_collect_cd_fan(struct device *dev, struct cd_list *
>  /* ======== fw_attributes (component: lenovo-wmi-capdata 01) ======== */
>  
>  struct tunable_attr_01 {
> -	struct capdata01 *capdata;
>  	struct device *dev;
> -	u32 feature_id;
> -	u32 device_id;
> -	u32 type_id;
> +	u8 feature_id;
> +	u8 device_id;
> +	u8 type_id;
> +	u8 cd_mode_id; /* mode arg for searching capdata */
> +	u8 cv_mode_id; /* mode arg for set/get current_value */
>  };
>  
>  static struct tunable_attr_01 ppt_pl1_spl = {
> @@ -716,7 +717,7 @@ static ssize_t attr_capdata01_show(struct kobject *kobj,
>  	int value, ret;
>  
>  	attribute_id = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> -				    LWMI_GZ_THERMAL_MODE_CUSTOM, tunable_attr->type_id);
> +				    tunable_attr->cd_mode_id, tunable_attr->type_id);
>  
>  	ret = lwmi_cd01_get_data(priv->cd01_list, attribute_id, &capdata);
>  	if (ret)
> @@ -782,7 +783,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
>  		return -EBUSY;
>  
>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> -				 mode, tunable_attr->type_id);
> +				 tunable_attr->cd_mode_id, tunable_attr->type_id);
>  
>  	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
>  	if (ret)
> @@ -795,6 +796,8 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
>  	if (value < capdata.min_value || value > capdata.max_value)
>  		return -EINVAL;
>  
> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> +				 tunable_attr->cv_mode_id, tunable_attr->type_id);
>  	args.arg1 = value;
>  
>  	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_SET,
> @@ -828,13 +831,16 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
>  	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
>  	struct wmi_method_args_32 args;
>  	enum thermal_mode mode;
> -	int retval;
> -	int ret;
> +	int retval, ret;
>  
>  	ret = lwmi_om_notifier_call(&mode);
>  	if (ret)
>  		return ret;
>  
> +	/* If "no-mode" is the supported mode, ensure we never send current mode */
> +	if (tunable_attr->cv_mode_id == LWMI_GZ_THERMAL_MODE_NONE)
> +		mode = tunable_attr->cv_mode_id;
> +
>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>  				 mode, tunable_attr->type_id);
>  
> @@ -847,6 +853,85 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
>  	return sysfs_emit(buf, "%d\n", retval);
>  }
>  
> +/**
> + * lwmi_attr_01_is_supported() - Determine if the given attribute is supported.
> + * @tunable_attr: The attribute to verify.
> + *
> + * First check if the attribute has a corresponding capdata01 table in the cd01
> + * module under the "custom" mode (0xff). If that is not present then check if
> + * there is a corresponding "no-mode" (0x00) entry. If either of those passes,
> + * check capdata->supported for values > 0. If capdata is available, attempt to
> + * determine the set/get mode for the current value property using a similar
> + * pattern. If the value returned by either custom or no-mode is 0, or we get
> + * an error, we assume that mode is not supported. If any of the above checks
> + * fail then the attribute is not fully supported.
> + *
> + * The probed cd_mode_id/cv_mode_id are stored on the tunable_attr for later
> + * reference.
> + *
> + * Return: Support level, or an error code.
> + */
> +static int lwmi_attr_01_is_supported(struct tunable_attr_01 *tunable_attr)
> +{
> +	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
> +	u8 mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
> +	struct wmi_method_args_32 args;
> +	struct capdata01 capdata;
> +	int retval, ret;
> +
> +	/* Determine tunable_attr->cd_mode_id */
> +no_mode_fallback_1:
> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> +				 mode, tunable_attr->type_id);
> +
> +	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
> +	if (ret && mode) {
> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);

Add include.

> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
> +		goto no_mode_fallback_1;

Is it possible to make a helper so you don't need these back gotos?

> +	}
> +	if (ret)
> +		goto not_supported;
> +	if (!capdata.supported) {
> +		ret = -EOPNOTSUPP;
> +		goto not_supported;
> +	}
> +
> +	tunable_attr->cd_mode_id = mode;
> +
> +	/* Determine tunable_attr->cv_mode_id */
> +	mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
> +no_mode_fallback_2:
> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> +				 mode, tunable_attr->type_id);
> +
> +	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET,
> +				    (unsigned char *)&args, sizeof(args),
> +				    &retval);
> +	if ((ret && mode) || (!retval && mode)) {
> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
> +		goto no_mode_fallback_2;

Same question here?

> +	}
> +	if (ret)
> +		goto not_supported;
> +	if (retval == 0) {
> +		ret = -EOPNOTSUPP;
> +		goto not_supported;
> +	}
> +
> +	tunable_attr->cv_mode_id = mode;
> +	dev_dbg(tunable_attr->dev, "cd_mode_id: %02x%02x%02x%02x, cv_mode_id: %#08x attribute support level: %x\n",
> +		tunable_attr->device_id, tunable_attr->feature_id, tunable_attr->cd_mode_id,
> +		tunable_attr->type_id, args.arg0, capdata.supported);
> +
> +	return capdata.supported;
> +
> +not_supported:
> +	dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> +	return ret;
> +}
> +
>  /* Lenovo WMI Other Mode Attribute macros */
>  #define __LWMI_ATTR_RO(_func, _name)                                  \
>  	{                                                             \
> @@ -970,19 +1055,21 @@ static int lwmi_om_fw_attr_add(struct lwmi_om_priv *priv)
>  	}
>  
>  	for (i = 0; i < ARRAY_SIZE(cd01_attr_groups) - 1; i++) {
> -		err = sysfs_create_group(&priv->fw_attr_kset->kobj,
> -					 cd01_attr_groups[i].attr_group);
> -		if (err)
> -			goto err_remove_groups;
> -
>  		cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev;
> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0) {

Reverse logic and use continue.

> +			err = sysfs_create_group(&priv->fw_attr_kset->kobj,
> +						 cd01_attr_groups[i].attr_group);
> +			if (err)
> +				goto err_remove_groups;
> +		}
>  	}
>  	return 0;
>  
>  err_remove_groups:
>  	while (i--)
> -		sysfs_remove_group(&priv->fw_attr_kset->kobj,
> -				   cd01_attr_groups[i].attr_group);
> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0)

Reverse logic + continue.

> +			sysfs_remove_group(&priv->fw_attr_kset->kobj,
> +					   cd01_attr_groups[i].attr_group);

You need to add braces for multiline constructs.

>  
>  	kset_unregister(priv->fw_attr_kset);
>  
> 

-- 
 i.

On February 24, 2026 12:47:56 AM PST, "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com> wrote:
>On Tue, 24 Feb 2026, Derek J. Clark wrote:
>
>> Adds lwmi_is_attr_01_supported, and only creates the attribute subfolder
>> if the attribute is supported by the hardware. Due to some poorly
>> implemented BIOS, this is a multi-step sequence of events. This is
>> because:
>> - Some BIOS support getting the capability data from custom mode (0xff),
>>   while others only support it in no-mode (0x00).
>> - Similarly, some BIOS support get/set for the current value from custom
>>   mode (0xff), while others only support it in no-mode (0x00).
>> - Some BIOS report capability data for a method that is not fully
>>   implemented.
>> - Some BIOS have methods fully implemented, but no complimentary
>>   capability data.
>> 
>> To ensure we only expose fully implemented methods with corresponding
>> capability data, we check each outcome before reporting that an
>> attribute can be supported.
>> 
>> Checking for lwmi_is_attr_01_supported during remove is not done to
>> ensure that we don't attempt to call cd01 or send WMI events if one of
>> the interfaces being removed was the cause of the driver unloading.
>> 
>
>> While adding members to tunable_attr_01, remove unused capdata pointer
>> and limit size of all ID's to the appropriate size.
>
>Please don't mix changes like this. Create a seprate patch for it.
>
>> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
>> Reported-by: Kurt Borja <kuurtb@gmail.com>
>> Closes: https://lore.kernel.org/platform-driver-x86/DG60P3SHXR8H.3NSEHMZ6J7XRC@gmail.com/
>> Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
>> ---
>>  drivers/platform/x86/lenovo/wmi-other.c | 117 +++++++++++++++++++++---
>>  1 file changed, 102 insertions(+), 15 deletions(-)
>> 
>> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
>> index 95886df39c8d..f3f12303e379 100644
>> --- a/drivers/platform/x86/lenovo/wmi-other.c
>> +++ b/drivers/platform/x86/lenovo/wmi-other.c
>> @@ -545,11 +545,12 @@ static void lwmi_om_fan_info_collect_cd_fan(struct device *dev, struct cd_list *
>>  /* ======== fw_attributes (component: lenovo-wmi-capdata 01) ======== */
>>  
>>  struct tunable_attr_01 {
>> -	struct capdata01 *capdata;
>>  	struct device *dev;
>> -	u32 feature_id;
>> -	u32 device_id;
>> -	u32 type_id;
>> +	u8 feature_id;
>> +	u8 device_id;
>> +	u8 type_id;
>> +	u8 cd_mode_id; /* mode arg for searching capdata */
>> +	u8 cv_mode_id; /* mode arg for set/get current_value */
>>  };
>>  
>>  static struct tunable_attr_01 ppt_pl1_spl = {
>> @@ -716,7 +717,7 @@ static ssize_t attr_capdata01_show(struct kobject *kobj,
>>  	int value, ret;
>>  
>>  	attribute_id = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> -				    LWMI_GZ_THERMAL_MODE_CUSTOM, tunable_attr->type_id);
>> +				    tunable_attr->cd_mode_id, tunable_attr->type_id);
>>  
>>  	ret = lwmi_cd01_get_data(priv->cd01_list, attribute_id, &capdata);
>>  	if (ret)
>> @@ -782,7 +783,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
>>  		return -EBUSY;
>>  
>>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> -				 mode, tunable_attr->type_id);
>> +				 tunable_attr->cd_mode_id, tunable_attr->type_id);
>>  
>>  	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
>>  	if (ret)
>> @@ -795,6 +796,8 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
>>  	if (value < capdata.min_value || value > capdata.max_value)
>>  		return -EINVAL;
>>  
>> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> +				 tunable_attr->cv_mode_id, tunable_attr->type_id);
>>  	args.arg1 = value;
>>  
>>  	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_SET,
>> @@ -828,13 +831,16 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
>>  	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
>>  	struct wmi_method_args_32 args;
>>  	enum thermal_mode mode;
>> -	int retval;
>> -	int ret;
>> +	int retval, ret;
>>  
>>  	ret = lwmi_om_notifier_call(&mode);
>>  	if (ret)
>>  		return ret;
>>  
>> +	/* If "no-mode" is the supported mode, ensure we never send current mode */
>> +	if (tunable_attr->cv_mode_id == LWMI_GZ_THERMAL_MODE_NONE)
>> +		mode = tunable_attr->cv_mode_id;
>> +
>>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>>  				 mode, tunable_attr->type_id);
>>  
>> @@ -847,6 +853,85 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
>>  	return sysfs_emit(buf, "%d\n", retval);
>>  }
>>  
>> +/**
>> + * lwmi_attr_01_is_supported() - Determine if the given attribute is supported.
>> + * @tunable_attr: The attribute to verify.
>> + *
>> + * First check if the attribute has a corresponding capdata01 table in the cd01
>> + * module under the "custom" mode (0xff). If that is not present then check if
>> + * there is a corresponding "no-mode" (0x00) entry. If either of those passes,
>> + * check capdata->supported for values > 0. If capdata is available, attempt to
>> + * determine the set/get mode for the current value property using a similar
>> + * pattern. If the value returned by either custom or no-mode is 0, or we get
>> + * an error, we assume that mode is not supported. If any of the above checks
>> + * fail then the attribute is not fully supported.
>> + *
>> + * The probed cd_mode_id/cv_mode_id are stored on the tunable_attr for later
>> + * reference.
>> + *
>> + * Return: Support level, or an error code.
>> + */
>> +static int lwmi_attr_01_is_supported(struct tunable_attr_01 *tunable_attr)
>> +{
>> +	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
>> +	u8 mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
>> +	struct wmi_method_args_32 args;
>> +	struct capdata01 capdata;
>> +	int retval, ret;
>> +
>> +	/* Determine tunable_attr->cd_mode_id */
>> +no_mode_fallback_1:
>> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> +				 mode, tunable_attr->type_id);
>> +
>> +	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
>> +	if (ret && mode) {
>> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
>
>Add include.
>
>> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
>> +		goto no_mode_fallback_1;
>
>Is it possible to make a helper so you don't need these back gotos?
>

Sure. How about I put both modes into an array and loop through them, passing the values to a function that will evaluate it. I can break if there is a match and throw an error if there's no match at the end.

>> +	}
>> +	if (ret)
>> +		goto not_supported;
>> +	if (!capdata.supported) {
>> +		ret = -EOPNOTSUPP;
>> +		goto not_supported;
>> +	}
>> +
>> +	tunable_attr->cd_mode_id = mode;
>> +
>> +	/* Determine tunable_attr->cv_mode_id */
>> +	mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
>> +no_mode_fallback_2:
>> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
>> +				 mode, tunable_attr->type_id);
>> +
>> +	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET,
>> +				    (unsigned char *)&args, sizeof(args),
>> +				    &retval);
>> +	if ((ret && mode) || (!retval && mode)) {
>> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
>> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
>> +		goto no_mode_fallback_2;
>
>Same question here?
>
>> +	}
>> +	if (ret)
>> +		goto not_supported;
>> +	if (retval == 0) {
>> +		ret = -EOPNOTSUPP;
>> +		goto not_supported;
>> +	}
>> +
>> +	tunable_attr->cv_mode_id = mode;
>> +	dev_dbg(tunable_attr->dev, "cd_mode_id: %02x%02x%02x%02x, cv_mode_id: %#08x attribute support level: %x\n",
>> +		tunable_attr->device_id, tunable_attr->feature_id, tunable_attr->cd_mode_id,
>> +		tunable_attr->type_id, args.arg0, capdata.supported);
>> +
>> +	return capdata.supported;
>> +
>> +not_supported:
>> +	dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
>> +	return ret;
>> +}
>> +
>>  /* Lenovo WMI Other Mode Attribute macros */
>>  #define __LWMI_ATTR_RO(_func, _name)                                  \
>>  	{                                                             \
>> @@ -970,19 +1055,21 @@ static int lwmi_om_fw_attr_add(struct lwmi_om_priv *priv)
>>  	}
>>  
>>  	for (i = 0; i < ARRAY_SIZE(cd01_attr_groups) - 1; i++) {
>> -		err = sysfs_create_group(&priv->fw_attr_kset->kobj,
>> -					 cd01_attr_groups[i].attr_group);
>> -		if (err)
>> -			goto err_remove_groups;
>> -
>>  		cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev;
>> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0) {
>
>Reverse logic and use continue.
>
>> +			err = sysfs_create_group(&priv->fw_attr_kset->kobj,
>> +						 cd01_attr_groups[i].attr_group);
>> +			if (err)
>> +				goto err_remove_groups;
>> +		}
>>  	}
>>  	return 0;
>>  
>>  err_remove_groups:
>>  	while (i--)
>> -		sysfs_remove_group(&priv->fw_attr_kset->kobj,
>> -				   cd01_attr_groups[i].attr_group);
>> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0)
>
>Reverse logic + continue.
>
>> +			sysfs_remove_group(&priv->fw_attr_kset->kobj,
>> +					   cd01_attr_groups[i].attr_group);
>
>You need to add braces for multiline constructs.
>
>>  
>>  	kset_unregister(priv->fw_attr_kset);
>>  
>> 
>

On Wed, 25 Feb 2026, Derek J. Clark wrote:

> On February 24, 2026 12:47:56 AM PST, "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com> wrote:
> >On Tue, 24 Feb 2026, Derek J. Clark wrote:
> >
> >> Adds lwmi_is_attr_01_supported, and only creates the attribute subfolder
> >> if the attribute is supported by the hardware. Due to some poorly
> >> implemented BIOS, this is a multi-step sequence of events. This is
> >> because:
> >> - Some BIOS support getting the capability data from custom mode (0xff),
> >>   while others only support it in no-mode (0x00).
> >> - Similarly, some BIOS support get/set for the current value from custom
> >>   mode (0xff), while others only support it in no-mode (0x00).
> >> - Some BIOS report capability data for a method that is not fully
> >>   implemented.
> >> - Some BIOS have methods fully implemented, but no complimentary
> >>   capability data.
> >> 
> >> To ensure we only expose fully implemented methods with corresponding
> >> capability data, we check each outcome before reporting that an
> >> attribute can be supported.
> >> 
> >> Checking for lwmi_is_attr_01_supported during remove is not done to
> >> ensure that we don't attempt to call cd01 or send WMI events if one of
> >> the interfaces being removed was the cause of the driver unloading.
> >> 
> >
> >> While adding members to tunable_attr_01, remove unused capdata pointer
> >> and limit size of all ID's to the appropriate size.
> >
> >Please don't mix changes like this. Create a seprate patch for it.
> >
> >> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> >> Reported-by: Kurt Borja <kuurtb@gmail.com>
> >> Closes: https://lore.kernel.org/platform-driver-x86/DG60P3SHXR8H.3NSEHMZ6J7XRC@gmail.com/
> >> Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
> >> ---
> >>  drivers/platform/x86/lenovo/wmi-other.c | 117 +++++++++++++++++++++---
> >>  1 file changed, 102 insertions(+), 15 deletions(-)
> >> 
> >> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> >> index 95886df39c8d..f3f12303e379 100644
> >> --- a/drivers/platform/x86/lenovo/wmi-other.c
> >> +++ b/drivers/platform/x86/lenovo/wmi-other.c
> >> @@ -545,11 +545,12 @@ static void lwmi_om_fan_info_collect_cd_fan(struct device *dev, struct cd_list *
> >>  /* ======== fw_attributes (component: lenovo-wmi-capdata 01) ======== */
> >>  
> >>  struct tunable_attr_01 {
> >> -	struct capdata01 *capdata;
> >>  	struct device *dev;
> >> -	u32 feature_id;
> >> -	u32 device_id;
> >> -	u32 type_id;
> >> +	u8 feature_id;
> >> +	u8 device_id;
> >> +	u8 type_id;
> >> +	u8 cd_mode_id; /* mode arg for searching capdata */
> >> +	u8 cv_mode_id; /* mode arg for set/get current_value */
> >>  };
> >>  
> >>  static struct tunable_attr_01 ppt_pl1_spl = {
> >> @@ -716,7 +717,7 @@ static ssize_t attr_capdata01_show(struct kobject *kobj,
> >>  	int value, ret;
> >>  
> >>  	attribute_id = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> >> -				    LWMI_GZ_THERMAL_MODE_CUSTOM, tunable_attr->type_id);
> >> +				    tunable_attr->cd_mode_id, tunable_attr->type_id);
> >>  
> >>  	ret = lwmi_cd01_get_data(priv->cd01_list, attribute_id, &capdata);
> >>  	if (ret)
> >> @@ -782,7 +783,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
> >>  		return -EBUSY;
> >>  
> >>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> >> -				 mode, tunable_attr->type_id);
> >> +				 tunable_attr->cd_mode_id, tunable_attr->type_id);
> >>  
> >>  	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
> >>  	if (ret)
> >> @@ -795,6 +796,8 @@ static ssize_t attr_current_value_store(struct kobject *kobj,
> >>  	if (value < capdata.min_value || value > capdata.max_value)
> >>  		return -EINVAL;
> >>  
> >> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> >> +				 tunable_attr->cv_mode_id, tunable_attr->type_id);
> >>  	args.arg1 = value;
> >>  
> >>  	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_SET,
> >> @@ -828,13 +831,16 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
> >>  	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
> >>  	struct wmi_method_args_32 args;
> >>  	enum thermal_mode mode;
> >> -	int retval;
> >> -	int ret;
> >> +	int retval, ret;
> >>  
> >>  	ret = lwmi_om_notifier_call(&mode);
> >>  	if (ret)
> >>  		return ret;
> >>  
> >> +	/* If "no-mode" is the supported mode, ensure we never send current mode */
> >> +	if (tunable_attr->cv_mode_id == LWMI_GZ_THERMAL_MODE_NONE)
> >> +		mode = tunable_attr->cv_mode_id;
> >> +
> >>  	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> >>  				 mode, tunable_attr->type_id);
> >>  
> >> @@ -847,6 +853,85 @@ static ssize_t attr_current_value_show(struct kobject *kobj,
> >>  	return sysfs_emit(buf, "%d\n", retval);
> >>  }
> >>  
> >> +/**
> >> + * lwmi_attr_01_is_supported() - Determine if the given attribute is supported.
> >> + * @tunable_attr: The attribute to verify.
> >> + *
> >> + * First check if the attribute has a corresponding capdata01 table in the cd01
> >> + * module under the "custom" mode (0xff). If that is not present then check if
> >> + * there is a corresponding "no-mode" (0x00) entry. If either of those passes,
> >> + * check capdata->supported for values > 0. If capdata is available, attempt to
> >> + * determine the set/get mode for the current value property using a similar
> >> + * pattern. If the value returned by either custom or no-mode is 0, or we get
> >> + * an error, we assume that mode is not supported. If any of the above checks
> >> + * fail then the attribute is not fully supported.
> >> + *
> >> + * The probed cd_mode_id/cv_mode_id are stored on the tunable_attr for later
> >> + * reference.
> >> + *
> >> + * Return: Support level, or an error code.
> >> + */
> >> +static int lwmi_attr_01_is_supported(struct tunable_attr_01 *tunable_attr)
> >> +{
> >> +	struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev);
> >> +	u8 mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
> >> +	struct wmi_method_args_32 args;
> >> +	struct capdata01 capdata;
> >> +	int retval, ret;
> >> +
> >> +	/* Determine tunable_attr->cd_mode_id */
> >> +no_mode_fallback_1:
> >> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> >> +				 mode, tunable_attr->type_id);
> >> +
> >> +	ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata);
> >> +	if (ret && mode) {
> >> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> >
> >Add include.
> >
> >> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
> >> +		goto no_mode_fallback_1;
> >
> >Is it possible to make a helper so you don't need these back gotos?
> >
> 
> Sure. How about I put both modes into an array and loop through them, 
> passing the values to a function that will evaluate it. I can break if 
> there is a match and throw an error if there's no match at the end.

It would probably work okay with a loop (which you've basically done now 
in a custom way using that goto) and array.

> >> +	}
> >> +	if (ret)
> >> +		goto not_supported;
> >> +	if (!capdata.supported) {
> >> +		ret = -EOPNOTSUPP;
> >> +		goto not_supported;
> >> +	}
> >> +
> >> +	tunable_attr->cd_mode_id = mode;
> >> +
> >> +	/* Determine tunable_attr->cv_mode_id */
> >> +	mode = LWMI_GZ_THERMAL_MODE_CUSTOM;
> >> +no_mode_fallback_2:
> >> +	args.arg0 = LWMI_ATTR_ID(tunable_attr->device_id, tunable_attr->feature_id,
> >> +				 mode, tunable_attr->type_id);
> >> +
> >> +	ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET,
> >> +				    (unsigned char *)&args, sizeof(args),
> >> +				    &retval);
> >> +	if ((ret && mode) || (!retval && mode)) {
> >> +		dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> >> +		mode = LWMI_GZ_THERMAL_MODE_NONE;
> >> +		goto no_mode_fallback_2;
> >
> >Same question here?
> >
> >> +	}
> >> +	if (ret)
> >> +		goto not_supported;
> >> +	if (retval == 0) {
> >> +		ret = -EOPNOTSUPP;
> >> +		goto not_supported;
> >> +	}
> >> +
> >> +	tunable_attr->cv_mode_id = mode;
> >> +	dev_dbg(tunable_attr->dev, "cd_mode_id: %02x%02x%02x%02x, cv_mode_id: %#08x attribute support level: %x\n",
> >> +		tunable_attr->device_id, tunable_attr->feature_id, tunable_attr->cd_mode_id,
> >> +		tunable_attr->type_id, args.arg0, capdata.supported);
> >> +
> >> +	return capdata.supported;
> >> +
> >> +not_supported:
> >> +	dev_dbg(tunable_attr->dev, "Attribute id %x not supported\n", args.arg0);
> >> +	return ret;
> >> +}
> >> +
> >>  /* Lenovo WMI Other Mode Attribute macros */
> >>  #define __LWMI_ATTR_RO(_func, _name)                                  \
> >>  	{                                                             \
> >> @@ -970,19 +1055,21 @@ static int lwmi_om_fw_attr_add(struct lwmi_om_priv *priv)
> >>  	}
> >>  
> >>  	for (i = 0; i < ARRAY_SIZE(cd01_attr_groups) - 1; i++) {
> >> -		err = sysfs_create_group(&priv->fw_attr_kset->kobj,
> >> -					 cd01_attr_groups[i].attr_group);
> >> -		if (err)
> >> -			goto err_remove_groups;
> >> -
> >>  		cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev;
> >> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0) {
> >
> >Reverse logic and use continue.
> >
> >> +			err = sysfs_create_group(&priv->fw_attr_kset->kobj,
> >> +						 cd01_attr_groups[i].attr_group);
> >> +			if (err)
> >> +				goto err_remove_groups;
> >> +		}
> >>  	}
> >>  	return 0;
> >>  
> >>  err_remove_groups:
> >>  	while (i--)
> >> -		sysfs_remove_group(&priv->fw_attr_kset->kobj,
> >> -				   cd01_attr_groups[i].attr_group);
> >> +		if (lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr) > 0)
> >
> >Reverse logic + continue.
> >
> >> +			sysfs_remove_group(&priv->fw_attr_kset->kobj,
> >> +					   cd01_attr_groups[i].attr_group);
> >
> >You need to add braces for multiline constructs.
> >
> >>  
> >>  	kset_unregister(priv->fw_attr_kset);
> >>  
> >> 
> >
> 

-- 
 i.