Subject: Re: [RFC PATCH net-next 07/12] Documentation: networking: dsa: mention integration with devlink

From: Andrew Lunn <[email-masked]>
Date: Thu, 25 Feb 2021 02:20:18 +0100

On Sun, Feb 21, 2021 at 11:33:50PM +0200, Vladimir Oltean wrote:
> From: Vladimir Oltean <[email-masked]>
> 
> Add a short summary of the devlink features supported by the DSA core.
> 
> Signed-off-by: Vladimir Oltean <[email-masked]>
> ---
>  Documentation/networking/dsa/dsa.rst | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/Documentation/networking/dsa/dsa.rst b/Documentation/networking/dsa/dsa.rst
> index 3c6560a43ae0..463b48714fe9 100644
> --- a/Documentation/networking/dsa/dsa.rst
> +++ b/Documentation/networking/dsa/dsa.rst
> @@ -394,6 +394,7 @@ DSA currently leverages the following subsystems:
>  - MDIO/PHY library: ``drivers/net/phy/phy.c``, ``mdio_bus.c``
>  - Switchdev:``net/switchdev/*``
>  - Device Tree for various of_* functions
> +- Devlink: ``net/core/devlink.c``
>  
>  MDIO/PHY library
>  ----------------
> @@ -433,6 +434,32 @@ more specifically with its VLAN filtering portion when configuring VLANs on top
>  of per-port slave network devices. As of today, the only SWITCHDEV objects
>  supported by DSA are the FDB and VLAN objects.
>  
> +Devlink
> +-------
> +
> +DSA registers one devlink device per each physical switch in the fabric.

"per each" sounds wrong to my ears. per on its own is better.

> +For each devlink device, every physical port (i.e. user ports, CPU ports, DSA
> +links and unused ports) is exposed as a devlink port.

I would probably use "or", instead of "and". 

> +
> +DSA drivers can make use of the following devlink features:
> +- Regions: debugging feature which allows user space to dump driver-defined
> +  areas of hardware information in a low-level, binary format. Both global
> +  regions as well as per-port regions are supported. Since address tables and
> +  VLAN tables are only inspectable by core iproute2 tools (ip-link, bridge) on
> +  user ports, devlink regions can be created for dumping these tables on the
> +  non-user ports too.

You might also add that additional details which don't fit the
iproute2 model can be included in regions dumps, since the format is
not restricted.

Reviewed-by: Andrew Lunn <[email-masked]>

    Andrew