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Message-ID: <21503e42-64c7-4ba1-a6b5-b27cb19af429@amd.com>
Date: Wed, 10 Dec 2025 09:43:45 -0600
From: Mario Limonciello <mario.limonciello@....com>
To: Nitin Joshi <nitjoshi@...il.com>, hansg@...nel.org,
ilpo.jarvinen@...ux.intel.com
Cc: platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
njoshi1@...ovo.com, Mark Pearson <mpearson-lenovo@...ebb.ca>
Subject: Re: [PATCH v2 2/2] platform/x86: thinkpad_acpi: Add sysfs to display
details of damaged device.
On 12/10/25 9:11 AM, Nitin Joshi wrote:
> Add new sysfs interface to identify the impacted component with location of
> device.
>
> Reviewed-by: Mark Pearson <mpearson-lenovo@...ebb.ca>
> Signed-off-by: Nitin Joshi<nitjoshi@...il.com>
> ---
> .../admin-guide/laptops/thinkpad-acpi.rst | 13 +-
> drivers/platform/x86/lenovo/thinkpad_acpi.c | 112 +++++++++++++++++-
> 2 files changed, 121 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
> index 94349e5f1298..3a9190ac47d0 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 4cf365550bcb..a092d57d995d 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;
> @@ -11108,7 +11124,95 @@ static int hwdd_command(int command, int *output)
> return 0;
> }
>
> -/* sysfs type-c damage detection capability */
> +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)))
> + continue;
> +
> + if (port_status & BIT(i)) {
> + *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;
> + }
Since this is always visible aren't you missing a case for
!ucdd_supported? I would think you should be returning -ENODEV.
Although arguably it would be better to control visibility of the sysfs
attribute based upon ucdd_supported. You can simplify
hwdd_detail_show() too then.
> +
> + if (!damage_detected)
> + count += sysfs_emit_at(buf, count, "No damage detected\n");
> +
> + return count;
> +}
> +
> +/* sysfs typc damage detection capability */
> static ssize_t hwdd_status_show(struct device *dev,
> struct device_attribute *attr,
> char *buf)
> @@ -11134,9 +11238,11 @@ 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
> };
>
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