From: Vladimir Oltean <olteanv@gmail.com>
To: Martyn Welch <martyn.welch@collabora.com>
Cc: Andrew Lunn <andrew@lunn.ch>,
Vivien Didelot <vivien.didelot@gmail.com>,
Florian Fainelli <f.fainelli@gmail.com>,
netdev@vger.kernel.org, kernel@collabora.com,
Russell King <rmk+kernel@armlinux.org.uk>
Subject: Re: mv88e6240 configuration broken for B850v3
Date: Mon, 6 Dec 2021 21:37:30 +0200 [thread overview]
Message-ID: <20211206193730.oubyveywniyvptfk@skbuf> (raw)
In-Reply-To: <3d6c6226e47374cf92d604bc6c711e59d76e3175.camel@collabora.com>
On Mon, Dec 06, 2021 at 07:24:56PM +0000, Martyn Welch wrote:
> On Mon, 2021-12-06 at 20:50 +0200, Vladimir Oltean wrote:
> > On Mon, Dec 06, 2021 at 06:37:44PM +0000, Martyn Welch wrote:
> > > On Mon, 2021-12-06 at 20:31 +0200, Vladimir Oltean wrote:
> > > > On Mon, Dec 06, 2021 at 06:26:25PM +0000, Martyn Welch wrote:
> > > > > On Mon, 2021-12-06 at 17:44 +0000, Martyn Welch wrote:
> > > > > > On Fri, 2021-12-03 at 17:25 +0100, Andrew Lunn wrote:
> > > > > > > > Hi Andrew,
> > > > > > >
> > > > > > > Adding Russell to Cc:
> > > > > > >
> > > > > > > > I'm currently in the process of updating the GE B850v3
> > > > > > > > [1] to
> > > > > > > > run
> > > > > > > > a
> > > > > > > > newer kernel than the one it's currently running.
> > > > > > >
> > > > > > > Which kernel exactly. We like bug reports against net-next,
> > > > > > > or
> > > > > > > at
> > > > > > > least the last -rc.
> > > > > > >
> > > > > >
> > > > > > I tested using v5.15-rc3 and that was also affected.
> > > > > >
> > > > >
> > > > > I've just tested v5.16-rc4 (sorry - just realised I previously
> > > > > wrote
> > > > > v5.15-rc3, it was v5.16-rc3...) and that was exactly the same.
> > > >
> > > > Just to clarify: you're saying that you're on v5.16-rc4 and that
> > > > if
> > > > you
> > > > revert commit 3be98b2d5fbc ("net: dsa: Down cpu/dsa ports phylink
> > > > will
> > > > control"), the link works again?
> > > >
> > >
> > > Correct
> > >
> > > > It is a bit strange that the external ports negotiate at
> > > > 10Mbps/Full,
> > > > is that the link speed you intend the ports to work at?
> > >
> > > Yes, that's 100% intentional due to what's connected to to those
> > > ports
> > > and the environment it works in.
> > >
> > > Martyn
> >
> > Just out of curiosity, can you try this change? It looks like a
> > simple
> > case of mismatched conditions inside the mv88e6xxx driver between
> > what
> > is supposed to force the link down and what is supposed to force it
> > up:
> >
> > diff --git a/net/dsa/port.c b/net/dsa/port.c
> > index 20f183213cbc..d235270babf7 100644
> > --- a/net/dsa/port.c
> > +++ b/net/dsa/port.c
> > @@ -1221,7 +1221,7 @@ int dsa_port_link_register_of(struct dsa_port
> > *dp)
> > if (of_phy_is_fixed_link(dp->dn) || phy_np) {
> > if (ds->ops->phylink_mac_link_down)
> > ds->ops->phylink_mac_link_down(ds, port,
> > - MLO_AN_FIXED, PHY_INTERFACE_MODE_NA);
> > + MLO_AN_PHY, PHY_INTERFACE_MODE_NA);
> > return dsa_port_phylink_register(dp);
> > }
> > return 0;
>
> Yes, that appears to also make it work.
>
> Martyn
Well, I just pointed out what the problem is, I don't know how to solve
it, honest! :)
It's clear that the code is wrong, because it's in an "if" block that
checks for "of_phy_is_fixed_link(dp->dn) || phy_np" but then it omits
the "phy_np" part of it. On the other hand we can't just go ahead and
say "if (phy_np) mode = MLO_AN_PHY; else mode = MLO_AN_FIXED;" because
MLO_AN_INBAND is also a valid option that we may be omitting. So we'd
have to duplicate part of the logic from phylink_parse_mode(), which
does not appear ideal at all. What would be ideal is if this fabricated
phylink call would not be done at all, but I don't know enough about the
systems that need it, I expect Andrew knows more.
next prev parent reply other threads:[~2021-12-06 19:37 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-03 9:06 mv88e6240 configuration broken for B850v3 Martyn Welch
2021-12-03 16:25 ` Andrew Lunn
2021-12-06 17:44 ` Martyn Welch
2021-12-06 18:26 ` Martyn Welch
2021-12-06 18:31 ` Vladimir Oltean
2021-12-06 18:37 ` Martyn Welch
2021-12-06 18:50 ` Vladimir Oltean
2021-12-06 19:24 ` Martyn Welch
2021-12-06 19:37 ` Vladimir Oltean [this message]
2021-12-06 19:53 ` Andrew Lunn
2021-12-06 20:01 ` Vladimir Oltean
2021-12-06 20:18 ` Russell King (Oracle)
2021-12-06 20:29 ` Vladimir Oltean
2021-12-07 14:09 ` Andrew Lunn
2021-12-06 21:44 ` Vladimir Oltean
2021-12-06 22:13 ` Russell King (Oracle)
2021-12-06 20:07 ` Russell King (Oracle)
2021-12-06 20:23 ` Vladimir Oltean
2021-12-06 20:51 ` Russell King (Oracle)
2021-12-06 21:13 ` Vladimir Oltean
2021-12-06 21:27 ` Russell King (Oracle)
2021-12-06 21:49 ` Russell King (Oracle)
2021-12-06 23:27 ` Vladimir Oltean
2021-12-07 0:58 ` Russell King (Oracle)
2021-12-07 13:24 ` Vladimir Oltean
2021-12-07 13:59 ` Russell King (Oracle)
2021-12-07 14:37 ` Vladimir Oltean
2021-12-07 14:53 ` Russell King (Oracle)
2021-12-06 21:51 ` Vladimir Oltean
2021-12-06 22:17 ` Andrew Lunn
2021-12-06 22:22 ` Russell King (Oracle)
2021-12-06 23:44 ` Vladimir Oltean
2021-12-07 2:06 ` Andrew Lunn
2021-12-07 12:48 ` Vladimir Oltean
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