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

[Hans de Goede <hansg@kernel.org>]

Hi,

On 8-Dec-25 8:19 AM, Nitin wrote:
> 
> On 12/3/25 22:16, Mark Pearson wrote:
>> On Wed, Dec 3, 2025, at 5:18 AM, Nitin wrote:
>>> Hi Hans,
>>>
>>> Thank you for reviewing this patch.
>>>
>>> On 12/3/25 16:52, Hans de Goede wrote:
>>>> Hi,
>>>>
>>>> Interesting new feature. A few small remarks on the proposed
>>>> sysfs API below.
>>>>
>>>> On 3-Dec-25 4:40 AM, Nitin Joshi wrote:
>>>>> Thinkpads are adding the ability to detect and report hardware damage
>>>>> status. Add new sysfs interface to identify the impacted component
>>>>> with status.
>>>>> 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>
>>>>> ---
>>>>>    .../admin-guide/laptops/thinkpad-acpi.rst     |  26 +++
>>>>>    drivers/platform/x86/lenovo/thinkpad_acpi.c   | 179 ++++++++++++++++++
>>>>>    2 files changed, 205 insertions(+)
>>>>>
>>>>> diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
>>>>> index 4ab0fef7d440..4a3220529489 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 +1577,31 @@ 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 impacted component.
>>>>> +Initial support is available for the USB-C replaceable connector.
>>>>> +
>>>>> +The available commands are::
>>>>> +
>>>>> +        cat /sys/devices/platform/thinkpad_acpi/hwdd_status
>>>>> +
>>>>> +This value displays device type and location of device with damage status.
>>>>> +For example:
>>>>> +if no damage is detected:
>>>>> +  No damage detected
>>>>> +if damage detected:
>>>>> +  Damage detected:
>>>>> +  Device: TYPE-C
>>>>> +  Location: Base, Right side, Center port
>>>>> +
>>>>> +The property is read-only. If feature is not supported then sysfs
>>>>> +class is not created.
>>>> Nitpick: s/class/attribute/ classes are standardized sysfs
>>>> interfaces living under /sys/class/ which this is not.
>>> Ack, I will modify it.
>>>> Besides the nitpick I'm wondering if we do not want to make
>>>> this a little bit more friendly / easy for software to parse ?
>>>>
>>>> ATM this seems focused on a human directly reading
>>>> the output but what if we want some sort of automation,
>>>> like e.g. a Linux version of the Lenovo Vantage sw parsing
>>>> this in the future?
>>>>
>>>> Note I've no specific suggestions for how to make this
>>>> easier to parse, this is just an observation.
>>> Thank you for pointing this out.  I am open for suggestions and will
>>> re-check regarding its use case in lenovo vantage in future.
>>>
>> I'd not considered it from this perspective.
>>
>> One concern is that it could be multiple devices in multiple location - so breaking it up into too many pieces becomes difficult.
>>
>> What if we did:
>>    hwdd_status - 1 or 0 if damage detected
>>    hwdd_detail - list of damaged items with their location (could be multiple). e.g.
>>      TYPE-C: Base, Right side, Center port

So I assume this would then output one line per damaged "item", it would
be good to document this (1 line per damaged item) in the sysfs ABI docs.

>> If hwdd_status is 0 then hwdd_detail would display "No damage detected"
> 
> Thank you, Mark ! I am OK with this suggestion.
> 
> Hans / Ilpo - Any comment on this ? Thanks

Yes this sounds good to me. 

Regards,

Hans