Re: [PATCH net-next 2/4] net/mlx5: Expose serial numbers in devlink info

[Simon Horman <horms@kernel.org>]

On Wed, Mar 19, 2025 at 12:39:59PM +0100, Jiri Pirko wrote:
> Tue, Mar 18, 2025 at 06:38:58PM +0100, horms@kernel.org wrote:
> >On Tue, Mar 18, 2025 at 04:36:25PM +0100, Jiri Pirko wrote:
> >> From: Jiri Pirko <jiri@nvidia.com>
> >> 
> >> Devlink info allows to expose serial number and board serial number
> >> Get the values from PCI VPD and expose it.
> >> 
> >> $ devlink dev info
> >> pci/0000:08:00.0:
> >>   driver mlx5_core
> >>   serial_number e4397f872caeed218000846daa7d2f49
> >>   board.serial_number MT2314XZ00YA
> >
> >Hi Jiri,
> >
> >I'm sorry if this is is somehow obvious, but what is
> >the difference between the serial number and board serial number
> >(yes, I do see that they are different numbers :)
> 
> Quoting Documentation/networking/devlink/devlink-info.rst:
> 
>    * - ``serial_number``
>      - Serial number of the device.
> 
>        This is usually the serial number of the ASIC, also often available
>        in PCI config space of the device in the *Device Serial Number*
>        capability.
> 
>        The serial number should be unique per physical device.
>        Sometimes the serial number of the device is only 48 bits long (the
>        length of the Ethernet MAC address), and since PCI DSN is 64 bits long
>        devices pad or encode additional information into the serial number.
>        One example is adding port ID or PCI interface ID in the extra two bytes.
>        Drivers should make sure to strip or normalize any such padding
>        or interface ID, and report only the part of the serial number
>        which uniquely identifies the hardware. In other words serial number
>        reported for two ports of the same device or on two hosts of
>        a multi-host device should be identical.
> 
>    * - ``board.serial_number``
>      - Board serial number of the device.
> 
>        This is usually the serial number of the board, often available in
>        PCI *Vital Product Data*.

Thanks, I should have known that :)