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Subject: Re: PHY reset question
To:     Florian Fainelli <f.fainelli@gmail.com>,
        Oleksij Rempel <o.rempel@pengutronix.de>,
        Andrew Lunn <andrew@lunn.ch>
Cc:     David Jander <david@protonic.nl>, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        Russell King <linux@armlinux.org.uk>, mkl@pengutronix.de
References: <20201006080424.GA6988@pengutronix.de>
 <2cc5ea02-707e-dbb5-c081-4c5202bd5815@gmail.com>
From:   Marek Vasut <marex@denx.de>
Message-ID: <42d4c4b2-d3ea-9130-ef7f-3d1955116fdc@denx.de>
Date:   Tue, 6 Oct 2020 22:24:14 +0200
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On 10/6/20 9:36 PM, Florian Fainelli wrote:
[...]
>> - Use compatible ("compatible = "ethernet-phy-id0022.1560") in the
>> devicetree,
>>    so that reading the PHYID is not needed
>>    - easy to solve.
>>    Disadvantage:
>>    - losing PHY auto-detection capability
>>    - need a new devicetree if different PHY is used (for example in
>> different
>>      board revision)
> 
> Or you can punt that to the boot loader to be able to tell the
> difference and populate different compatible, or even manage the PHY
> reset to be able to read the actual PHY OUI. To me that is still the
> best solution around.

Wasn't there some requirement for Linux to be bootloader-independent ?
Some systems cannot replace their bootloaders, e.g. if the bootloader is
in ROM, so this might not be a solution.

>> - modify PHY framework to deassert reset before identifying the PHY.
>>    Disadvantages?

If this happens on MX6 with FEC, can you please try these two patches?

https://patchwork.ozlabs.org/project/netdev/patch/20201006135253.97395-1-marex@denx.de/

https://patchwork.ozlabs.org/project/netdev/patch/20201006202029.254212-1-marex@denx.de/

Thanks!