Re: PHY reset question

From: Marek Vasut
Date: Tue Oct 06 2020 - 16:24:48 EST


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@xxxxxxx/

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

Thanks!