[PATCH net-next 0/2] net: mediatek: Add MT7621 TRGMII mode support

René van Dorst opensource at vdorst.com
Mon Jun 17 14:33:12 PDT 2019

Quoting Andrew Lunn <andrew at lunn.ch>:

> On Sun, Jun 16, 2019 at 08:20:08PM +0200, René van Dorst wrote:
>> Like many other mediatek SOCs, the MT7621 SOC and the internal  
>> MT7530 switch both
>> supports TRGMII mode. MT7621 TRGMII speed is 1200MBit.
> Hi René

Hi Andrew,

> Is TRGMII used only between the SoC and the Switch? Or does external
> ports of the switch also support 1200Mbit/s? If external ports support
> this, what does ethtool show for Speed?

Only the first GMAC of the SOC and port 6 of the switch supports this mode.
The switch can be internal in the SOC but also a separate chip.

PHYLINK and ethertool reports the link as 1Gbit.
The link is fixed-link with speed = 1000.

dmesg output with unposted PHYLINK patches:
[    5.236763] mt7530 mdio-bus:1f: configuring for fixed/trgmii link mode
[    5.249813] mt7530 mdio-bus:1f: phylink_mac_config:  
mode=fixed/trgmii/1Gbps/Full adv=00,00000000,00000220 pause=12 link=1  
[    6.389435] mtk_soc_eth 1e100000.ethernet eth0: phylink_mac_config:  
mode=fixed/trgmii/1Gbps/Full adv=00,00000000,00000220 pause=12 link=1  

# ethtool eth0
Settings for eth0:
          Supported ports: [ MII ]
          Supported link modes:   1000baseT/Full
          Supported pause frame use: No
          Supports auto-negotiation: No
          Supported FEC modes: Not reported
          Advertised link modes:  1000baseT/Full
          Advertised pause frame use: No
          Advertised auto-negotiation: No
          Advertised FEC modes: Not reported
          Speed: 1000Mb/s
          Duplex: Full
          Port: MII
          PHYAD: 0
          Transceiver: internal
          Auto-negotiation: on
          Current message level: 0x000000ff (255)
                                 drv probe link timer ifdown ifup rx_err tx_err
          Link detected: yes

I already have report from a MT7623 user that this patch gives issues.

I send v2 of the patch if I fixed that issue.

Also I think it is better to add a XTAL frequency check.
The PLL values are only valid with a 40MHz crystal.

Any other comments for v2?



>      Thanks
> 	Andrew

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