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Date:   Thu, 30 Sep 2021 21:38:24 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Saravana Kannan <saravanak@google.com>
Cc:     Vladimir Oltean <olteanv@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, Len Brown <lenb@kernel.org>,
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        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        linux-acpi@vger.kernel.org
Subject: Re: [PATCH v1 1/2] driver core: fw_devlink: Add support for
 FWNODE_FLAG_BROKEN_PARENT
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> Btw, do we have non-DSA networking devices where fw_devlink=on
> delaying PHY probes is causing an issue?

I don't know if issues have been reported, but the realtek driver has
had problems in the past when the generic driver is used. Take a look
at r8169_mdio_register(), it does something similar to DSA.

What is going to make things interesting is that phy_attach_direct()
is called in two different contexts. During the MAC drivers probe, it
is O.K. to return EPROBE_DEFER, and let the MAC driver try again
later, if we know there is a specific PHY driver for it. But when
called during the MAC drivers open() op, -EPROBE_DEFER is not
allowed. What to do then is an interesting question.

     Andrew