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Message-ID: <6b4733f4a5bedd465b7ee5ea435dcdaf12a61321.camel@redhat.com>
Subject: Re: [PATCH 1/4] net: dsa: Extend the dsa_switch structure to hold
 info about HSR ports
From:   Paolo Abeni <pabeni@redhat.com>
To:     Lukasz Majewski <lukma@denx.de>, Tristram.Ha@microchip.com,
        Eric Dumazet <edumazet@google.com>, davem@davemloft.net,
        Woojung Huh <woojung.huh@microchip.com>,
        Vladimir Oltean <olteanv@gmail.com>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>, UNGLinuxDriver@microchip.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Thu, 31 Aug 2023 11:10:00 +0200
In-Reply-To: <20230829121132.414335-2-lukma@denx.de>
References: <20230829121132.414335-1-lukma@denx.de>
         <20230829121132.414335-2-lukma@denx.de>
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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.
>=20
> 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.
>=20
> Signed-off-by: Lukasz Majewski <lukma@denx.de>
> ---
>  include/net/dsa.h | 3 +++
>  1 file changed, 3 insertions(+)
>=20
> 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;
> =20
> +	/* 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