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Date:   Tue, 7 Jun 2022 15:05:40 +0100
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Luiz Angelo Daros de Luca <luizluca@gmail.com>
Cc:     Alvin =?utf-8?Q?=C5=A0ipraga?= <ALSI@bang-olufsen.dk>,
        Alvin =?utf-8?Q?=C5=A0ipraga?= <alvin@pqrs.dk>,
        Linus Walleij <linus.walleij@linaro.org>,
        Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net] net: dsa: realtek: rtl8365mb: fix GMII caps for
 ports with internal PHY
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On Tue, Jun 07, 2022 at 10:52:48AM -0300, Luiz Angelo Daros de Luca wrote:
> > > > Luiz, Russel:
> > > >
> > > > Commit a5dba0f207e5 ought to have had a Fixes: tag I think, because it
> > > > claims to have been fixing a regression in the net-next tree - is that
> > > > right? I seem to have missed both referenced commits when they were
> > > > posted and never hit this issue personally. I only found things now
> > > > during some other refactoring and the test for GMII looked weird to me
> > > > so I went and investigated.
> > > >
> > > > Could you please help me identify that Fixes: tag? Just for my own
> > > > understanding of what caused this added requirement for GMII on ports
> > > > with internal PHY.
> > >
> > > I have absolutely no idea. I don't think any "requirement" has ever been
> > > added - phylib has always defaulted to GMII, so as the driver stood when
> > > it was first submitted on Oct 18 2021, I don't see how it could have
> > > worked, unless the DT it was being tested with specified a phy-mode of
> > > "internal". As you were the one who submitted it, you would have a
> > > better idea.
> > >
> > > The only suggestion I have is to bisect to find out exactly what caused
> > > the GMII vs INTERNAL issue to crop up.
> >
> > Alright, thanks for the quick response. Maybe Luiz has a better idea, otherwise
> > I will try bisecting if I find the time.
> 
> I don't know. I just got hit by the issue after a rebase (sorry, I
> don't know exactly from which commit I was rebasing).
> But I did test the net (!-next) and left a working commit note. You
> can diff 3dd7d40b43..a5dba0f20.
> If I'm to guess, I would blame:
> 
> 21bd64bd717de: net: dsa: consolidate phylink creation

Why do you suspect that commit? I fail to see any functional change in
that commit that would cause the problem.

-- 
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