Subject: Re: [RFC PATCH net-next v3 1/8] dt-bindings: phy: mediatek,xfi-pextp: add new bindings

From: Daniel Golle <[email-masked]>
Date: Tue, 12 Dec 2023 16:42:45 +0000

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/