Re: [PATCH 1/4] net: dsa: Extend the dsa_switch structure to hold info about HSR ports

[Paolo Abeni <pabeni@redhat.com>]

On Tue, 2023-08-29 at 14:11 +0200, Lukasz Majewski wrote:
> Information about HSR aware ports in a DSA switch can be helpful when
> one needs tags to be adjusted before the HSR frame is sent.
> 
> For example - with ksz9477 switch - the TAG needs to be adjusted to have
> both HSR ports marked in tag to allow execution of HW based frame
> duplication.
> 
> Signed-off-by: Lukasz Majewski <lukma@denx.de>
> ---
>  include/net/dsa.h | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index d309ee7ed04b..15274afc42bb 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -470,6 +470,9 @@ struct dsa_switch {
>  	/* Number of switch port queues */
>  	unsigned int		num_tx_queues;
>  
> +	/* Bitmask indicating ports supporting HSR */
> +	u16                     hsr_ports;
> +
>  	/* Drivers that benefit from having an ID associated with each
>  	 * offloaded LAG should set this to the maximum number of
>  	 * supported IDs. DSA will then maintain a mapping of _at

Out of sheer ignorance, I think this new field does not belong to
dsa_switch, at least not in this form. AFAICS there is no current hard
limitation on the number of ports a DSA switch can handle at the API
level, and this will introduce an hard one.

I think you are better off keeping this field in the KSZ-specific
struct. If you really want to keep it here you should remove the above
limitation somehow (possibly a query op to check if a given port is HSR
aware???)

In any case this series looks like net-next material, does not apply
correctly to net-next and net-next is currently closed. You can share a
new version as RFC or wait for net-next to re-open in ~2w.

Cheers,

Paolo