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From:   DENG Qingfang <dqfext@gmail.com>
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     Sasha Levin <sashal@kernel.org>, stable@vger.kernel.org,
        Sean Wang <sean.wang@mediatek.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        "open list:MEDIATEK SWITCH DRIVER" <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>
Subject: Re: [PATCH 4.19.y] net: dsa: mt7530: disable learning on standalone ports
Date:   Thu,  2 Sep 2021 13:36:19 +0800
Message-Id: <20210902053619.1824464-1-dqfext@gmail.com>
In-Reply-To: <YSi8Ky3GqBjnxbhC@kroah.com>
References: <20210824055509.1316124-1-dqfext@gmail.com> <YSUQV3jhfbhbf5Ct@sashalap> <CALW65ja3hYGmEqcWZzifP2-0WsJOnxcUXsey2ZH5vDbD0-nDeQ@mail.gmail.com> <YSi8Ky3GqBjnxbhC@kroah.com>
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On Fri, Aug 27, 2021 at 12:19:23PM +0200, Greg KH wrote:
> On Tue, Aug 24, 2021 at 11:57:53PM +0800, DENG Qingfang wrote:
> > Standalone ports should have address learning disabled, according to
> > the documentation:
> > https://www.kernel.org/doc/html/v5.14-rc7/networking/dsa/dsa.html#bridge-layer
> > dsa_switch_ops on 5.10 or earlier does not have .port_bridge_flags
> > function so it has to be done differently.
> > 
> > I've identified an issue related to this.
> 
> What issue is that?  Where was it reported?

See Florian's message here
https://lore.kernel.org/stable/20210317003549.3964522-2-f.fainelli@gmail.com/

> 
> > > 2. A partial backport of this patch?
> > 
> > The other part does not actually fix anything.
> 
> Then why is it not ok to just take the whole thing?
> 
> When backporting not-identical-patches, something almost always goes
> wrong, so we prefer to take the original commit when ever possible.

Okay. MDB and tag ops can be backported as is, and broadcast/multicast
flooding can be implemented in .port_egress_floods. 

> 
> thanks,
> 
> greg k-h