Re: [PATCH] arm64: dts: ti: k3-am625-beagleplay: Use the builtin mdio bus

From: Nishanth Menon
Date: Fri Jan 12 2024 - 09:26:01 EST


On 15:20-20240112, Sjoerd Simons wrote:
> On Fri, 2024-01-12 at 07:50 -0600, Nishanth Menon wrote:
> > On 13:44-20240112, Sjoerd Simons wrote:
> > > The beagleplay dts was using a bit-bang gpio mdio bus as a work-
> > > around
> > > for errata i2329. However since commit d04807b80691 ("net:
> > > ethernet: ti:
> > > davinci_mdio: Add workaround for errata i2329") the mdio driver
> > > itself
> > > already takes care of this errata for effected silicon, which
> > > landed
> > > well before the beagleplay dts. So i suspect the reason for the
> > > workaround in upstream was simply due to copying the vendor dts.
> > >
> > > Switch the dts to the ti,cpsw-mdio instead so it described the
> > > actual
> > > hardware and is consistent with other AM625 based boards
> > >
> > > Signed-off-by: Sjoerd Simons <sjoerd@xxxxxxxxxxxxx>
> > >
> > > ---
> >
> > We have had issues with the ethernet integration previously (also why
> > ethernet in u-boot is not yet functional on beagleplay[1]).
> >
> > https://openbeagle.org/beagleplay/beagleplay/-/issues/101
> >
> > we should probably do a 1000 boot nfs test or something to ensure
> > this
> > doesn't introduce regressions (I recollect mdio wasn't stable on
> > beagleplay) and switching to bitbang driver stopped all complains.
>
> I can do a longer test with that over the weekend sure; For reference
> I'm seeing issues in u-boot as well on initial probe with these
> changes, but i've not seen the same on the linux side.
>
> Do you remember with what kernel versions users saw the mdio
> instabilities? I wonder if that was a version with the commit mentioned
> that includes the errata fix for the mdio driver.
>

we were on TI 5.10 kernel (the image that went into production) and it
did have errata fix (I am not sure if it is similar or same as what
finally went into upstream now).. I have started an automated multiple
boot test on my end as well..

The signature as I recollect was spurious link Down and Up logs
(though the cable is not physically disconnected).. been a bit of
time.. so my memory on exact signature might be vague.

--
Regards,
Nishanth Menon
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