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Date:   Tue, 12 Dec 2023 16:42:45 +0000
From:   Daniel Golle <daniel@makrotopia.org>
To:     Conor Dooley <conor@kernel.org>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Chunfeng Yun <chunfeng.yun@mediatek.com>,
        Vinod Koul <vkoul@kernel.org>,
        Kishon Vijay Abraham I <kishon@kernel.org>,
        Felix Fietkau <nbd@nbd.name>, John Crispin <john@phrozen.org>,
        Sean Wang <sean.wang@mediatek.com>,
        Mark Lee <Mark-MC.Lee@mediatek.com>,
        Lorenzo Bianconi <lorenzo@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
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        Russell King <linux@armlinux.org.uk>,
        Alexander Couzens <lynxis@fe80.eu>,
        Qingfang Deng <dqfext@gmail.com>,
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        Philipp Zabel <p.zabel@pengutronix.de>, netdev@vger.kernel.org,
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        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-phy@lists.infradead.org
Subject: Re: [RFC PATCH net-next v3 1/8] dt-bindings: phy:
 mediatek,xfi-pextp: add new bindings
Message-ID: <ZXiNhSYDbowUiNvy@makrotopia.org>
References: <cover.1702352117.git.daniel@makrotopia.org>
 <b875f693f6d4367a610a12ef324584f3bf3a1c1c.1702352117.git.daniel@makrotopia.org>
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On Tue, Dec 12, 2023 at 04:21:38PM +0000, Conor Dooley wrote:
> On Tue, Dec 12, 2023 at 03:46:26AM +0000, Daniel Golle wrote:
> 
> > +  mediatek,usxgmii-performance-errata:
> > +    $ref: /schemas/types.yaml#/definitions/flag
> > +    description:
> > +      USXGMII0 on MT7988 suffers from a performance problem in 10GBase-R
> > +      mode which needs a work-around in the driver. The work-around is
> > +      enabled using this flag.
> 
> Why do you need a property for this if you know that it is present on
> the MT7988?

Because it is only present in one of the two SerDes channels.
Channel 0 needs the work-around, Channel 1 doesn't.

See also this commit in the vendor driver for reference[1].

We previously discussed that[2] and it was decided that a property
would be the prefered way to represent this as there aren't any other
per-instance differences which would justify another compatible.


[1]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/a500d94cd47e279015ce22947e1ce396a7516598%5E%21/#F0

[2]: https://patchwork.kernel.org/comment/25592845/