Re: [PATCH v4 4/4] net: mdio: Add RTL9300 MDIO driver

[Chris Packham]

On 23/01/2025 16:41, Andrew Lunn wrote:
> On Wed, Jan 22, 2025 at 11:02:14PM +0000, Chris Packham wrote:
>> Hi Andrew,
>>
>> On 23/01/2025 10:47, Andrew Lunn wrote:
>>>> I believe the POLL_SEL configuration actually affects an internal port
>>>> polling unit. From the datasheets I have it seems pretty configurable, you
>>>> can tell it which phy registers to poll and what values indicate link
>>>> up/down (the defaults are conveniently setup to match the Realtek PHYs).
>>> You need to disable this. The linux PHY driver is driving the PHY, and
>>> the hardware has no idea what Linux is doing. Say the driver has
>>> changed the page to read a temperature sensor, when the switch does a
>>> poll. Rather than reading the link status, it gets some random value
>>> from the page containing the temperature sensor.
>> There's a mask that can be set via a register that can disable polling
>> for a port. The trick will be deciding when to do so.
> On probe. And leave is disabled. phylink will provide you with all the
> information you need about link up, what the link speed is etc. There
> is no need for PPU.

Works for me :P.