Re: [PATCH v3] net: dsa: mv88e6xxx: support RGMII cmode

Andrew Lunn
2022-08-26T00:06:14Z

On Thu, Aug 25, 2022 at 04:42:06PM -0700, Jakub Kicinski wrote:
> On Fri, 26 Aug 2022 01:26:59 +0200 Marek Behún wrote:
> > > Could you explain why? Is there an upstream-supported platform
> > > already in Linus's tree which doesn't boot or something?
> >
> > If you mean whether there is a device-tree of such a device, they I
> > don't think so, because AFAIK there isn't a device-tree with 6393 in
> > upstream Linux other than CN9130-CRB.
> >
> > But it is possible though that there is such a device which has
> > everything but the switch supported on older kernels, due to this RGMII
> > bug.
> >
> > I think RGMII should have been supported on this switch when I send the
> > patch adding support for it, and it is a bug that it is not, becuase
> > RGMII is supported for similar switches driven by mv88e6xxx driver
> > (6390, for example). I don't know why I overlooked it then.
> >
> > Note that I wouldn't consider adding support for USXGMII a fix, because
> > although the switch can do it, it was never done with this driver.
> >
> > But if you think it doesn't apply anyway, remove the Fixes tag. This is
> > just my opinion that it should stay.
>
> I see, I can only go by our general guidance of not treating omissions
> as fixes, but I lack the knowledge to be certain what's right here.
> Anyone willing to cast a tie-break vote? Andrew? net or net-next?

Stable rules say:

o It must fix a real bug that bothers people (not a, “This could be a problem…” type thing).

We know anything with a Fixes: tag pretty much gets considered as a
candidate for stable by the machine learning bot, even if we don't
mark it so. So i would say drop the Fixes: tag, it does not fulfil the
stable requirements.

Andrew