Re: [PATCH 2/2] dt-bindings: net: dsa: qca8k: add internal-PHY-to-PHY CPU link example

[Ziyang Huang <hzyitc@outlook.com>]

在 2025/3/4 22:11, Andrew Lunn 写道:
>> (Port0 and Port6). Could I just keep this or should I need to add a new
>> case ?
> 
> The existing examples are probably sufficient. Just check the text to
> make sure it does not limit it to ports 0 and 6.
> 
>>> So is this actually internally? Or do you have a IPQ50xx SoC connected
>>> to a qca8337 switch, with copper traces on a PCB? If so, it is not
>>> internal.
>>
>> The "internal" is used to describe the localcation of PHY not the link.
>> In current code, qca8k has supported to use a external PHY to do a
>> PHY-to-PHY link (Port0 and Port6). This patch make the internal PHYs
>> support it too (Port1-5).
>>
>> The followiing topology is existed in most IPQ50xx-based router:
>>      _______________________         _______________________
>>     |        IPQ5018        |       |        QCA8337        |
>>     | +------+   +--------+ |       | +--------+   +------+ |
>>     | | MAC0 |---| GE Phy |-+--MDI--+-|  Phy4  |---| MAC5 | |
>>     | +------+   +--------+ |       | +--------+   +------+ |
>>     | +------+   +--------+ |       | +--------+   +------+ |
>>     | | MAC1 |---| Uniphy |-+-SGMII-+-| SerDes |---| MAC0 | |
>>     | +------+   +--------+ |       | +--------+   +------+ |
>>     |_______________________|       |_______________________|
> 
> So logically, it does not matter if the PHY is internal or
> external. The patch would be the same. I've even see setups where the
> SGMII link would have a PHY, then a connection to a daughter board,
> and then a PHY back to SGMII before connecting to the switch. Running
> Ethernet over the connector is easier than SERDES lines.
> 
> So i would probably drop the word internal from this discussion,
> unless it is really relevant.
> 
> 	Andrew

Ok, will remove the word in next patch