[PATCH v5 1/2] platform/x86: thinkpad_acpi: Add support to detect hardware damage detection capability.

[PATCH v5 1/2] platform/x86: thinkpad_acpi: Add support to detect hardware damage detection capability.

[Nitin Joshi]

Thinkpads are adding the ability to detect and report hardware damage
status. Add new sysfs interface to identify whether hardware damage
is detected or not.

Initial support is available for the USB-C replaceable connector.

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Nitin Joshi<nitjoshi@gmail.com>
---
Changes since v1:
-Split patch between hwdd_status and hwdd_detail
-Incorporated review comments
Changes since v2:
-Control visibility of the sysfs attribute based upon ucdd_supported
Changes since v3:
-Fix documentation build warning
Changes since v4:
-Removed extra line
---
 .../admin-guide/laptops/thinkpad-acpi.rst     |  21 ++++
 drivers/platform/x86/lenovo/thinkpad_acpi.c   | 105 ++++++++++++++++++
 2 files changed, 126 insertions(+)

diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
index 4ab0fef7d440..2db05f718b11 100644
--- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst
+++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
@@ -54,6 +54,7 @@ detailed description):
 	- Setting keyboard language
 	- WWAN Antenna type
 	- Auxmac
+	- Hardware damage detection capability
 
 A compatibility table by model and feature is maintained on the web
 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
@@ -1576,6 +1577,26 @@ percentage level, above which charging will stop.
 The exact semantics of the attributes may be found in
 Documentation/ABI/testing/sysfs-class-power.
 
+Hardware damage detection capability
+------------------------------------
+
+sysfs attributes: hwdd_status
+
+Thinkpads are adding the ability to detect and report hardware damage.
+Add new sysfs interface to identify the damaged device status.
+Initial support is available for the USB-C replaceable connector.
+
+The command to check device damaged status is::
+
+        cat /sys/devices/platform/thinkpad_acpi/hwdd_status
+
+This value displays status of device damaged
+- 0 = Not Damaged
+- 1 = Damaged
+
+The property is read-only. If feature is not supported then sysfs
+attribute is not created.
+
 Multiple Commands, Module Parameters
 ------------------------------------
 
diff --git a/drivers/platform/x86/lenovo/thinkpad_acpi.c b/drivers/platform/x86/lenovo/thinkpad_acpi.c
index cc19fe520ea9..cb1f6dae9334 100644
--- a/drivers/platform/x86/lenovo/thinkpad_acpi.c
+++ b/drivers/platform/x86/lenovo/thinkpad_acpi.c
@@ -11080,6 +11080,106 @@ static const struct attribute_group auxmac_attr_group = {
 	.attrs = auxmac_attributes,
 };
 
+/*************************************************************************
+ * HWDD subdriver, for the Lenovo Hardware Damage Detection feature.
+ */
+
+#define HWDD_GET_DMG_USBC	0x80000001
+#define HWDD_GET_CAP		0
+#define HWDD_NOT_SUPPORTED	BIT(31)
+#define HWDD_SUPPORT_USBC	BIT(0)
+
+#define PORT_STATUS		GENMASK(7, 4)
+#define NUM_PORTS		4
+
+static bool hwdd_support_available;
+static bool ucdd_supported;
+
+static int hwdd_command(int command, int *output)
+{
+	acpi_handle hwdd_handle;
+
+	if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "HWDD", &hwdd_handle)))
+		return -ENODEV;
+
+	if (!acpi_evalf(hwdd_handle, output, NULL, "dd", command))
+		return -EIO;
+
+	return 0;
+}
+
+/* sysfs type-c damage detection capability */
+static ssize_t hwdd_status_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	unsigned int damage_status, port_status;
+	int err, i;
+
+	if (ucdd_supported) {
+		/* Get USB TYPE-C damage status */
+		err = hwdd_command(HWDD_GET_DMG_USBC, &damage_status);
+		if (err)
+			return err;
+
+		port_status = FIELD_GET(PORT_STATUS, damage_status);
+		for (i = 0; i < NUM_PORTS; i++) {
+			if (!(damage_status & BIT(i)))
+				continue;
+			if (port_status & BIT(i))
+				return sysfs_emit(buf, "1\n");
+		}
+	} else
+		return -ENODEV;
+
+	return sysfs_emit(buf, "0\n");
+}
+static DEVICE_ATTR_RO(hwdd_status);
+
+static struct attribute *hwdd_attributes[] = {
+	&dev_attr_hwdd_status.attr,
+	NULL
+};
+
+static umode_t hwdd_attr_is_visible(struct kobject *kobj,
+				struct attribute *attr, int n)
+{
+	return hwdd_support_available ? attr->mode : 0;
+}
+
+static const struct attribute_group hwdd_attr_group = {
+	.is_visible = hwdd_attr_is_visible,
+	.attrs = hwdd_attributes,
+};
+
+static int tpacpi_hwdd_init(struct ibm_init_struct *iibm)
+{
+	int err, output;
+
+	/* Below command checks the HWDD damage capability */
+	err = hwdd_command(HWDD_GET_CAP, &output);
+	if (err)
+		return err;
+
+	if (!(output & HWDD_NOT_SUPPORTED))
+		return -ENODEV;
+
+	hwdd_support_available = true;
+
+	/*
+	 * BIT(0) is assigned to check capability of damage detection is
+	 * supported for USB Type-C port or not.
+	 */
+	if (output & HWDD_SUPPORT_USBC)
+		ucdd_supported = true;
+
+	return err;
+}
+
+static struct ibm_struct hwdd_driver_data = {
+	.name = "hwdd",
+};
+
 /* --------------------------------------------------------------------- */
 
 static struct attribute *tpacpi_driver_attributes[] = {
@@ -11139,6 +11239,7 @@ static const struct attribute_group *tpacpi_groups[] = {
 	&kbdlang_attr_group,
 	&dprc_attr_group,
 	&auxmac_attr_group,
+	&hwdd_attr_group,
 	NULL,
 };
 
@@ -11752,6 +11853,10 @@ static struct ibm_init_struct ibms_init[] __initdata = {
 		.init = auxmac_init,
 		.data = &auxmac_data,
 	},
+	{
+		.init = tpacpi_hwdd_init,
+		.data = &hwdd_driver_data,
+	},
 };
 
 static int __init set_ibm_param(const char *val, const struct kernel_param *kp)
-- 
2.43.0

[PATCH v5 2/2] platform/x86: thinkpad_acpi: Add sysfs to display details of damaged device.

[Nitin Joshi]

Add new sysfs interface to identify the impacted component with location of
device.

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Nitin Joshi<nitjoshi@gmail.com>
---
Changes since v2:
-Control visibility of the sysfs attribute based upon ucdd_supported
Changes since v3:
-Fix documentation build warning
Changes since v4:
-Improved indentation and removed extra line
---
 .../admin-guide/laptops/thinkpad-acpi.rst     |  13 ++-
 drivers/platform/x86/lenovo/thinkpad_acpi.c   | 108 +++++++++++++++++-
 2 files changed, 118 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
index 2db05f718b11..3a37b14863a8 100644
--- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst
+++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
@@ -1580,7 +1580,7 @@ Documentation/ABI/testing/sysfs-class-power.
 Hardware damage detection capability
 ------------------------------------
 
-sysfs attributes: hwdd_status
+sysfs attributes: hwdd_status, hwdd_detail
 
 Thinkpads are adding the ability to detect and report hardware damage.
 Add new sysfs interface to identify the damaged device status.
@@ -1594,6 +1594,17 @@ This value displays status of device damaged
 - 0 = Not Damaged
 - 1 = Damaged
 
+The command to check location of damaged device is::
+
+        cat /sys/devices/platform/thinkpad_acpi/hwdd_detail
+
+This value displays location of damaged device having 1 line per damaged "item".
+For example:
+if no damage is detected:
+- No damage detected
+if damage detected:
+- TYPE-C: Base, Right side, Center port
+
 The property is read-only. If feature is not supported then sysfs
 attribute is not created.
 
diff --git a/drivers/platform/x86/lenovo/thinkpad_acpi.c b/drivers/platform/x86/lenovo/thinkpad_acpi.c
index cb1f6dae9334..2e317e13d984 100644
--- a/drivers/platform/x86/lenovo/thinkpad_acpi.c
+++ b/drivers/platform/x86/lenovo/thinkpad_acpi.c
@@ -11089,8 +11089,24 @@ static const struct attribute_group auxmac_attr_group = {
 #define HWDD_NOT_SUPPORTED	BIT(31)
 #define HWDD_SUPPORT_USBC	BIT(0)
 
-#define PORT_STATUS		GENMASK(7, 4)
-#define NUM_PORTS		4
+#define PORT_STATUS     GENMASK(7, 4)
+#define LID_STATUS      GENMASK(11, 8)
+#define BASE_STATUS     GENMASK(15, 12)
+#define POS_STATUS      GENMASK(3, 2)
+#define PANEL_STATUS    GENMASK(1, 0)
+
+#define PORT_DETAIL_OFFSET	16
+
+#define PANEL_TOP	0
+#define PANEL_BASE	1
+#define PANEL_LEFT	2
+#define PANEL_RIGHT	3
+
+#define POS_LEFT	0
+#define POS_CENTER	1
+#define POS_RIGHT	2
+
+#define NUM_PORTS	4
 
 static bool hwdd_support_available;
 static bool ucdd_supported;
@@ -11108,6 +11124,92 @@ static int hwdd_command(int command, int *output)
 	return 0;
 }
 
+static bool display_damage(char *buf, int *count, char *type, unsigned int dmg_status)
+{
+	unsigned char lid_status, base_status, port_status;
+	unsigned char loc_status, pos_status, panel_status;
+	bool damage_detected = false;
+	int i;
+
+	port_status = FIELD_GET(PORT_STATUS, dmg_status);
+	lid_status = FIELD_GET(LID_STATUS, dmg_status);
+	base_status = FIELD_GET(BASE_STATUS, dmg_status);
+	for (i = 0; i < NUM_PORTS; i++) {
+		if (!(dmg_status & BIT(i)) || !(port_status & BIT(i)))
+			continue;
+
+		*count += sysfs_emit_at(buf, *count, "%s: ", type);
+		loc_status = (dmg_status >> (PORT_DETAIL_OFFSET + (4 * i))) & 0xF;
+		pos_status = FIELD_GET(POS_STATUS, loc_status);
+		panel_status = FIELD_GET(PANEL_STATUS, loc_status);
+
+		if (lid_status & BIT(i))
+			*count += sysfs_emit_at(buf, *count, "Lid, ");
+		if (base_status & BIT(i))
+			*count += sysfs_emit_at(buf, *count, "Base, ");
+
+		switch (pos_status) {
+		case PANEL_TOP:
+			*count += sysfs_emit_at(buf, *count, "Top, ");
+			break;
+		case PANEL_BASE:
+			*count += sysfs_emit_at(buf, *count, "Bottom, ");
+			break;
+		case PANEL_LEFT:
+			*count += sysfs_emit_at(buf, *count, "Left, ");
+			break;
+		case PANEL_RIGHT:
+			*count += sysfs_emit_at(buf, *count, "Right, ");
+			break;
+		default:
+			pr_err("Unexpected value %d in switch statement\n", pos_status);
+		};
+
+		switch (panel_status) {
+		case POS_LEFT:
+			*count += sysfs_emit_at(buf, *count, "Left port\n");
+			break;
+		case POS_CENTER:
+			*count += sysfs_emit_at(buf, *count, "Center port\n");
+			break;
+		case POS_RIGHT:
+			*count += sysfs_emit_at(buf, *count, "Right port\n");
+			break;
+		default:
+			*count += sysfs_emit_at(buf, *count, "Undefined\n");
+			break;
+		};
+		damage_detected = true;
+	}
+	return damage_detected;
+}
+
+/* sysfs type-c damage detection detail */
+static ssize_t hwdd_detail_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	bool damage_detected = false;
+	unsigned int damage_status;
+	int err, count = 0;
+
+	if (ucdd_supported) {
+		/* Get USB TYPE-C damage status */
+		err = hwdd_command(HWDD_GET_DMG_USBC, &damage_status);
+		if (err)
+			return err;
+
+		if (display_damage(buf, &count, "Type-C", damage_status))
+			damage_detected = true;
+	} else
+		return -ENODEV;
+
+	if (!damage_detected)
+		count += sysfs_emit_at(buf, count, "No damage detected\n");
+
+	return count;
+}
+
 /* sysfs type-c damage detection capability */
 static ssize_t hwdd_status_show(struct device *dev,
 				struct device_attribute *attr,
@@ -11135,9 +11237,11 @@ static ssize_t hwdd_status_show(struct device *dev,
 	return sysfs_emit(buf, "0\n");
 }
 static DEVICE_ATTR_RO(hwdd_status);
+static DEVICE_ATTR_RO(hwdd_detail);
 
 static struct attribute *hwdd_attributes[] = {
 	&dev_attr_hwdd_status.attr,
+	&dev_attr_hwdd_detail.attr,
 	NULL
 };
 
-- 
2.43.0

Re: [PATCH v5 1/2] platform/x86: thinkpad_acpi: Add support to detect hardware damage detection capability.

[Ilpo Järvinen]

On Wed, 17 Dec 2025, Nitin Joshi wrote:

> Thinkpads are adding the ability to detect and report hardware damage
> status. Add new sysfs interface to identify whether hardware damage
> is detected or not.
> 
> Initial support is available for the USB-C replaceable connector.
> 
> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> Signed-off-by: Nitin Joshi<nitjoshi@gmail.com>
> ---
> Changes since v1:
> -Split patch between hwdd_status and hwdd_detail
> -Incorporated review comments
> Changes since v2:
> -Control visibility of the sysfs attribute based upon ucdd_supported
> Changes since v3:
> -Fix documentation build warning
> Changes since v4:
> -Removed extra line
> ---
>  .../admin-guide/laptops/thinkpad-acpi.rst     |  21 ++++
>  drivers/platform/x86/lenovo/thinkpad_acpi.c   | 105 ++++++++++++++++++
>  2 files changed, 126 insertions(+)
> 
> diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
> index 4ab0fef7d440..2db05f718b11 100644
> --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst
> +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
> @@ -54,6 +54,7 @@ detailed description):
>  	- Setting keyboard language
>  	- WWAN Antenna type
>  	- Auxmac
> +	- Hardware damage detection capability
>  
>  A compatibility table by model and feature is maintained on the web
>  site, http://ibm-acpi.sf.net/. I appreciate any success or failure
> @@ -1576,6 +1577,26 @@ percentage level, above which charging will stop.
>  The exact semantics of the attributes may be found in
>  Documentation/ABI/testing/sysfs-class-power.
>  
> +Hardware damage detection capability
> +------------------------------------
> +
> +sysfs attributes: hwdd_status
> +
> +Thinkpads are adding the ability to detect and report hardware damage.
> +Add new sysfs interface to identify the damaged device status.
> +Initial support is available for the USB-C replaceable connector.
> +
> +The command to check device damaged status is::
> +
> +        cat /sys/devices/platform/thinkpad_acpi/hwdd_status
> +
> +This value displays status of device damaged
> +- 0 = Not Damaged
> +- 1 = Damaged
> +
> +The property is read-only. If feature is not supported then sysfs
> +attribute is not created.
> +
>  Multiple Commands, Module Parameters
>  ------------------------------------
>  
> diff --git a/drivers/platform/x86/lenovo/thinkpad_acpi.c b/drivers/platform/x86/lenovo/thinkpad_acpi.c
> index cc19fe520ea9..cb1f6dae9334 100644
> --- a/drivers/platform/x86/lenovo/thinkpad_acpi.c
> +++ b/drivers/platform/x86/lenovo/thinkpad_acpi.c
> @@ -11080,6 +11080,106 @@ static const struct attribute_group auxmac_attr_group = {
>  	.attrs = auxmac_attributes,
>  };
>  
> +/*************************************************************************
> + * HWDD subdriver, for the Lenovo Hardware Damage Detection feature.
> + */
> +
> +#define HWDD_GET_DMG_USBC	0x80000001
> +#define HWDD_GET_CAP		0
> +#define HWDD_NOT_SUPPORTED	BIT(31)
> +#define HWDD_SUPPORT_USBC	BIT(0)
> +
> +#define PORT_STATUS		GENMASK(7, 4)
> +#define NUM_PORTS		4
> +
> +static bool hwdd_support_available;
> +static bool ucdd_supported;
> +
> +static int hwdd_command(int command, int *output)
> +{
> +	acpi_handle hwdd_handle;
> +
> +	if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "HWDD", &hwdd_handle)))
> +		return -ENODEV;
> +
> +	if (!acpi_evalf(hwdd_handle, output, NULL, "dd", command))
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +/* sysfs type-c damage detection capability */
> +static ssize_t hwdd_status_show(struct device *dev,
> +				struct device_attribute *attr,
> +				char *buf)
> +{
> +	unsigned int damage_status, port_status;
> +	int err, i;
> +
> +	if (ucdd_supported) {
> +		/* Get USB TYPE-C damage status */
> +		err = hwdd_command(HWDD_GET_DMG_USBC, &damage_status);
> +		if (err)
> +			return err;
> +
> +		port_status = FIELD_GET(PORT_STATUS, damage_status);
> +		for (i = 0; i < NUM_PORTS; i++) {
> +			if (!(damage_status & BIT(i)))
> +				continue;
> +			if (port_status & BIT(i))
> +				return sysfs_emit(buf, "1\n");
> +		}
> +	} else
> +		return -ENODEV;

The usual approach is to first check not supported + return errno, then 
you don't even need "else". The same comment to the other patch.

-- 
 i.


> +
> +	return sysfs_emit(buf, "0\n");
> +}
> +static DEVICE_ATTR_RO(hwdd_status);
> +
> +static struct attribute *hwdd_attributes[] = {
> +	&dev_attr_hwdd_status.attr,
> +	NULL
> +};
> +
> +static umode_t hwdd_attr_is_visible(struct kobject *kobj,
> +				struct attribute *attr, int n)
> +{
> +	return hwdd_support_available ? attr->mode : 0;
> +}
> +
> +static const struct attribute_group hwdd_attr_group = {
> +	.is_visible = hwdd_attr_is_visible,
> +	.attrs = hwdd_attributes,
> +};
> +
> +static int tpacpi_hwdd_init(struct ibm_init_struct *iibm)
> +{
> +	int err, output;
> +
> +	/* Below command checks the HWDD damage capability */
> +	err = hwdd_command(HWDD_GET_CAP, &output);
> +	if (err)
> +		return err;
> +
> +	if (!(output & HWDD_NOT_SUPPORTED))
> +		return -ENODEV;
> +
> +	hwdd_support_available = true;
> +
> +	/*
> +	 * BIT(0) is assigned to check capability of damage detection is
> +	 * supported for USB Type-C port or not.
> +	 */
> +	if (output & HWDD_SUPPORT_USBC)
> +		ucdd_supported = true;
> +
> +	return err;
> +}
> +
> +static struct ibm_struct hwdd_driver_data = {
> +	.name = "hwdd",
> +};
> +
>  /* --------------------------------------------------------------------- */
>  
>  static struct attribute *tpacpi_driver_attributes[] = {
> @@ -11139,6 +11239,7 @@ static const struct attribute_group *tpacpi_groups[] = {
>  	&kbdlang_attr_group,
>  	&dprc_attr_group,
>  	&auxmac_attr_group,
> +	&hwdd_attr_group,
>  	NULL,
>  };
>  
> @@ -11752,6 +11853,10 @@ static struct ibm_init_struct ibms_init[] __initdata = {
>  		.init = auxmac_init,
>  		.data = &auxmac_data,
>  	},
> +	{
> +		.init = tpacpi_hwdd_init,
> +		.data = &hwdd_driver_data,
> +	},
>  };
>  
>  static int __init set_ibm_param(const char *val, const struct kernel_param *kp)
> 

Re: [PATCH v5 1/2] platform/x86: thinkpad_acpi: Add support to detect hardware damage detection capability.

[Nitin Joshi]

On 12/23/25 12:14, Ilpo Järvinen wrote:
> On Wed, 17 Dec 2025, Nitin Joshi wrote:
>
>> Thinkpads are adding the ability to detect and report hardware damage
>> status. Add new sysfs interface to identify whether hardware damage
>> is detected or not.
>>
>> Initial support is available for the USB-C replaceable connector.
>>
>> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
>> Signed-off-by: Nitin Joshi<nitjoshi@gmail.com>
>> ---
>> Changes since v1:
>> -Split patch between hwdd_status and hwdd_detail
>> -Incorporated review comments
>> Changes since v2:
>> -Control visibility of the sysfs attribute based upon ucdd_supported
>> Changes since v3:
>> -Fix documentation build warning
>> Changes since v4:
>> -Removed extra line
>> ---
>>   .../admin-guide/laptops/thinkpad-acpi.rst     |  21 ++++
>>   drivers/platform/x86/lenovo/thinkpad_acpi.c   | 105 ++++++++++++++++++
>>   2 files changed, 126 insertions(+)
>>
>> diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
>> index 4ab0fef7d440..2db05f718b11 100644
>> --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst
>> +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
>> @@ -54,6 +54,7 @@ detailed description):
>>   	- Setting keyboard language
>>   	- WWAN Antenna type
>>   	- Auxmac
>> +	- Hardware damage detection capability
>>   
>>   A compatibility table by model and feature is maintained on the web
>>   site, http://ibm-acpi.sf.net/. I appreciate any success or failure
>> @@ -1576,6 +1577,26 @@ percentage level, above which charging will stop.
>>   The exact semantics of the attributes may be found in
>>   Documentation/ABI/testing/sysfs-class-power.
>>   
>> +Hardware damage detection capability
>> +------------------------------------
>> +
>> +sysfs attributes: hwdd_status
>> +
>> +Thinkpads are adding the ability to detect and report hardware damage.
>> +Add new sysfs interface to identify the damaged device status.
>> +Initial support is available for the USB-C replaceable connector.
>> +
>> +The command to check device damaged status is::
>> +
>> +        cat /sys/devices/platform/thinkpad_acpi/hwdd_status
>> +
>> +This value displays status of device damaged
>> +- 0 = Not Damaged
>> +- 1 = Damaged
>> +
>> +The property is read-only. If feature is not supported then sysfs
>> +attribute is not created.
>> +
>>   Multiple Commands, Module Parameters
>>   ------------------------------------
>>   
>> diff --git a/drivers/platform/x86/lenovo/thinkpad_acpi.c b/drivers/platform/x86/lenovo/thinkpad_acpi.c
>> index cc19fe520ea9..cb1f6dae9334 100644
>> --- a/drivers/platform/x86/lenovo/thinkpad_acpi.c
>> +++ b/drivers/platform/x86/lenovo/thinkpad_acpi.c
>> @@ -11080,6 +11080,106 @@ static const struct attribute_group auxmac_attr_group = {
>>   	.attrs = auxmac_attributes,
>>   };
>>   
>> +/*************************************************************************
>> + * HWDD subdriver, for the Lenovo Hardware Damage Detection feature.
>> + */
>> +
>> +#define HWDD_GET_DMG_USBC	0x80000001
>> +#define HWDD_GET_CAP		0
>> +#define HWDD_NOT_SUPPORTED	BIT(31)
>> +#define HWDD_SUPPORT_USBC	BIT(0)
>> +
>> +#define PORT_STATUS		GENMASK(7, 4)
>> +#define NUM_PORTS		4
>> +
>> +static bool hwdd_support_available;
>> +static bool ucdd_supported;
>> +
>> +static int hwdd_command(int command, int *output)
>> +{
>> +	acpi_handle hwdd_handle;
>> +
>> +	if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "HWDD", &hwdd_handle)))
>> +		return -ENODEV;
>> +
>> +	if (!acpi_evalf(hwdd_handle, output, NULL, "dd", command))
>> +		return -EIO;
>> +
>> +	return 0;
>> +}
>> +
>> +/* sysfs type-c damage detection capability */
>> +static ssize_t hwdd_status_show(struct device *dev,
>> +				struct device_attribute *attr,
>> +				char *buf)
>> +{
>> +	unsigned int damage_status, port_status;
>> +	int err, i;
>> +
>> +	if (ucdd_supported) {
>> +		/* Get USB TYPE-C damage status */
>> +		err = hwdd_command(HWDD_GET_DMG_USBC, &damage_status);
>> +		if (err)
>> +			return err;
>> +
>> +		port_status = FIELD_GET(PORT_STATUS, damage_status);
>> +		for (i = 0; i < NUM_PORTS; i++) {
>> +			if (!(damage_status & BIT(i)))
>> +				continue;
>> +			if (port_status & BIT(i))
>> +				return sysfs_emit(buf, "1\n");
>> +		}
>> +	} else
>> +		return -ENODEV;
> The usual approach is to first check not supported + return errno, then
> you don't even need "else". The same comment to the other patch.

Ack , I will modify it and send next revision. Thank you for review.