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Date:   Tue, 11 Jul 2023 17:56:37 +0100
From:   Simon Horman <simon.horman@corigine.com>
To:     Vladimir Oltean <vladimir.oltean@nxp.com>
Cc:     netdev@vger.kernel.org, Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        UNGLinuxDriver@microchip.com,
        Xiaoliang Yang <xiaoliang.yang_1@nxp.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH net 1/3] net: mscc: ocelot: extend
 ocelot->fwd_domain_lock to cover ocelot->tas_lock
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References: <20230705104422.49025-1-vladimir.oltean@nxp.com>
 <20230705104422.49025-2-vladimir.oltean@nxp.com>
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On Wed, Jul 05, 2023 at 01:44:20PM +0300, Vladimir Oltean wrote:
> In a future commit we will have to call vsc9959_tas_guard_bands_update()
> from ocelot_port_update_active_preemptible_tcs(), and that will be
> impossible due to the AB/BA locking dependencies between
> ocelot->tas_lock and ocelot->fwd_domain_lock.
> 
> Just like we did in commit 3ff468ef987e ("net: mscc: ocelot: remove
> struct ocelot_mm_state :: lock"), the only solution is to expand the
> scope of ocelot->fwd_domain_lock for it to also serialize changes made
> to the Time-Aware Shaper, because those will have to result in a
> recalculation of cut-through TCs, which is something that depends on the
> forwarding domain.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Reviewed-by: Simon Horman <simon.horman@corigine.com>