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Subject: Re: phy_attach_direct()'s use of device_bind_driver()
To:     Saravana Kannan <saravanak@google.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Russell King <linux@armlinux.org.uk>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>
Cc:     Android Kernel Team <kernel-team@android.com>,
        netdev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Jon Hunter <jonathanh@nvidia.com>
References: <CAGETcx9YpCUMmHjyydMtOJP9SKBbVsHNB-9SspD9u=txJ12Gug@mail.gmail.com>
From:   Heiner Kallweit <hkallweit1@gmail.com>
Message-ID: <bb9ea9ed-cbf1-0712-2322-1373a7b01fca@gmail.com>
Date:   Wed, 10 Feb 2021 23:40:38 +0100
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On 10.02.2021 23:13, Saravana Kannan wrote:
> Hi,
> 
> This email was triggered by this other email[1].
> 
> Why is phy_attach_direct() directly calling device_bind_driver()
> instead of using bus_probe_device()? I'm asking because this is
> causing device links status to not get updated correctly and causes
> this[2] warning.
> 

The genphy driver is a fallback if no dedicated PHY driver matches the
PHY device. It doesn't match any device, therefore it needs to be
explicitly bound.

> We can fix the device links issue with something like this[3], but
> want to understand the reason for the current implementation of
> phy_attach_direct() before we go ahead and put in that fix.
> 
> Thanks,
> Saravana
> 
> [1] - https://lore.kernel.org/lkml/e11bc6a2-ec9d-ea3b-71f7-13c9f764bbfc@nvidia.com/#t
> [2] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com/
> [3] - https://lore.kernel.org/lkml/6a43e209-1d2d-b10a-4564-0289d54135d3@nvidia.com/
>