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From:   Saravana Kannan <saravanak@google.com>
Date:   Tue, 8 Nov 2022 12:56:15 -0800
Message-ID: <CAGETcx-=Z4wo8JaYJN=SjxirbgRoRvobN8zxm+BSHjwouHzeJg@mail.gmail.com>
Subject: Re: [PATCH net-next v2 08/11] of: property: Add device link support
 for PCS
To:     Rob Herring <robh@kernel.org>
Cc:     Sean Anderson <sean.anderson@seco.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>, netdev@vger.kernel.org,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Jakub Kicinski <kuba@kernel.org>, linux-kernel@vger.kernel.org,
        Andrew Lunn <andrew@lunn.ch>,
        Ioana Ciornei <ioana.ciornei@nxp.com>,
        Madalin Bucur <madalin.bucur@nxp.com>,
        "David S . Miller" <davem@davemloft.net>,
        Frank Rowand <frowand.list@gmail.com>,
        devicetree@vger.kernel.org
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On Mon, Nov 7, 2022 at 1:36 PM Rob Herring <robh@kernel.org> wrote:
>
> On Mon, Nov 7, 2022 at 2:50 PM Sean Anderson <sean.anderson@seco.com> wrote:
> >
> > On 11/7/22 15:22, Vladimir Oltean wrote:
> > > On Mon, Nov 07, 2022 at 02:10:10PM -0600, Rob Herring wrote:
> > >> On Thu, Nov 03, 2022 at 05:06:47PM -0400, Sean Anderson wrote:
> > >> > This adds device link support for PCS devices. Both the recommended
> > >> > pcs-handle and the deprecated pcsphy-handle properties are supported.
> > >> > This should provide better probe ordering.
> > >> >
> > >> > Signed-off-by: Sean Anderson <sean.anderson@seco.com>
> > >> > ---
> > >> >
> > >> > (no changes since v1)
> > >> >
> > >> >  drivers/of/property.c | 4 ++++
> > >> >  1 file changed, 4 insertions(+)
> > >>
> > >> Seems like no dependency on the rest of the series, so I can take this
> > >> patch?
> > >
> > > Is fw_devlink well-behaved these days, so as to not break (forever defer)
> > > the probing of the device having the pcs-handle, if no driver probed on
> > > the referenced PCS? Because the latter is what will happen if no one
> > > picks up Sean's patches to probe PCS devices in the usual device model
> > > way, I think.
> >
> > Last time [1], Saravana suggested to move this to the end of the series to
> > avoid such problems. FWIW, I just tried booting a LS1046A with the
> > following patches applied
> >
> > 01/11 (compatibles) 05/11 (device) 08/11 (link) 09/11 (consumer)
> > =================== ============== ============ ================
> > Y                   N              Y            N
> > Y                   Y              Y            Y
> > Y                   Y              Y            N
> > N                   Y              Y            N
> > N                   N              Y            N
> >
> > and all interfaces probed each time. So maybe it is safe to pick
> > this patch.
>
> Maybe? Just take it with the rest of the series.
>
> Acked-by: Rob Herring <robh@kernel.org>

Let's have Vladimir ack this. I'm not sure if it's fully safe yet. I
haven't done the necessary fixes for phy-handle yet, but I don't know
how pcs-handle and pcsphy-handle are used or if none of their uses
will hit the chicken and egg problem that some uses of phy-handle hit.

-Saravana