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From: Andrew Lunn <andrew@lunn.ch>
To: Joakim Zhang <qiangqing.zhang@nxp.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
	netdev <netdev@vger.kernel.org>, dl-linux-imx <linux-imx@nxp.com>
Subject: Re: [PATCH V1 net-next 0/3] net: stmmac: implement clocks
Date: Thu, 25 Feb 2021 14:14:16 +0100	[thread overview]
Message-ID: <YDeiqACL9Rtja6tH@lunn.ch> (raw)
In-Reply-To: <DB8PR04MB679510F099C88F6B4BA10970E69E9@DB8PR04MB6795.eurprd04.prod.outlook.com>

> Hi Andrew,
> 
> Thanks for you explanation, I still don't quite understand what the use case it is, could you give me more details, thanks a lot!
> AFAIK now, there are two connections methods, we can abstract the layer:
> 	MAC <-> MAC, there is no PHY attached. It seems to know as Fixed link, right?

Yes, this is the most common way of connecting a switch.

> 	MAC+PHY <-> PHY+MAC

Switches can be connected like this, but not often. Why pay for two
PHYs which you do not need?

> From your expression, you should use an external Ethernet switch, if
> yes, why Ethernet switch needs to use MDIO bus to access another
> MAC's(STMMAC) PHY?

The switch is on the same board as the MAC. Take a look at:
https://netdevconf.info/2.1/papers/distributed-switch-architecture.pdf

It explains the DSA architecture.

   Andrew

      reply	other threads:[~2021-02-25 13:15 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-23 10:48 [PATCH V1 net-next 0/3] net: stmmac: implement clocks Joakim Zhang
2021-02-23 10:48 ` [PATCH V1 net-next 1/3] net: stmmac: add clocks management for gmac driver Joakim Zhang
2021-02-23 16:46   ` Jakub Kicinski
2021-02-24  1:46     ` Joakim Zhang
2021-02-23 10:48 ` [PATCH V1 net-next 2/3] net: stmmac: add platform level clocks management Joakim Zhang
2021-02-23 10:48 ` [PATCH V1 net-next 3/3] net: stmmac: add platform level clocks management for i.MX Joakim Zhang
2021-02-23 16:45 ` [PATCH V1 net-next 0/3] net: stmmac: implement clocks Jakub Kicinski
2021-02-24  1:45   ` Joakim Zhang
2021-02-24  1:54     ` Jakub Kicinski
2021-02-24  2:13       ` Joakim Zhang
2021-02-24  2:34         ` Jakub Kicinski
2021-02-24  2:47           ` Joakim Zhang
2021-02-24  3:54             ` Florian Fainelli
2021-02-25  1:42               ` Joakim Zhang
2021-02-24  9:03           ` Joakim Zhang
2021-02-24 13:01       ` Andrew Lunn
2021-02-25  2:15         ` Joakim Zhang
     [not found]         ` <DB8PR04MB6795FAE4C1736AABDCA75FA7E69E9@DB8PR04MB6795.eurprd04.prod.outlook.com>
2021-02-25  2:33           ` Andrew Lunn
2021-02-25 11:48             ` Joakim Zhang
2021-02-25 13:14               ` Andrew Lunn [this message]

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