Subject: Re: [net-next] net: ethernet: rtsn: Add support for Renesas Ethernet-TSN

From: Niklas Söderlund <[email-masked]>
Date: Mon, 6 May 2024 16:05:33 +0200

Hi Andrew,

Thanks for this explanation, it helps understand what's going on.

On 2024-05-06 03:51:45 +0200, Andrew Lunn wrote:

> What PHY is this? Does it have C22 registers? Can it be identified via
> C22 registers 2 and 3?

The PHY in question is mv88q2110 (drivers/net/phy/marvell-88q2xxx.c), 
unfortunately I do not have a datasheet for it so I can't tell you much 
about it.

<snip>

> 
> So i would drop the compatible. See if C22 is sufficient to get the
> correct driver loaded.

- Remove C45 compatible; Remove C45 read/write in driver

  The PHY is identified as "Generic PHY", and the correct PHY driver is 
  not used. I can't test more than that as the generic PHY driver do not 
  implement some quirks I need to get the link up.

- Remove C45 compatible; Keep C45 read/write in driver

  The correct PHY driver is used and everything works.

- Keep C45 compatible; Remove C45 read/write in driver

  As described earlier in this thread, the MAC driver can't connect to 
  the PHY as the call-chain described earlier fails.

How would you suggest I move forward here? Shall I keep the C45 over C22 
read/write in the driver or can I do something else more clever?

-- 
Kind Regards,
Niklas Söderlund