Re: [PATCH net-next 7/7] net: dsa: mediatek: support EN751221 switch
From: Caleb James DeLisle
Date: Tue Sep 15 2026 - 14:26:25 EST
On 12/09/2026 02:08, Jakub Kicinski wrote:
On Wed, 9 Sep 2026 14:03:46 +0000 Caleb James DeLisle wrote:
The EcoNet EN751221 has either one, or two, onboard MT7530 switches.../drivers/net/dsa/mt7530.c: In function ‘en751221_trgmii_pair_setup’:
Every implementation of this SoC has one switch on die with the CPU,
but some chips - notably those with a "G" in the name, have a second
MT7530 as an MCM module.
The on-die MT7530 has 4 FE ports and 1 GE port. The MCM switch has all
gigabit ports.
The MCM switch connects to the SoC switch via a TRGMII link from port
5 on the SoC switch to port 6 on the MCM switch. This link undergoes
calibration on startup.
All known devices with the MCM present do not make any use of the ports
on the on-die switch, it is put into "passthrough" mode in which all
traffic is shuttled between port 6 and port 5 without alteration of the
DSA tags.
Add support for both the on-die and the MCM switch, and calibration of
the TRGMII link between them.
../drivers/net/dsa/mt7530.c:593:12: warning: variable ‘default_taps_ondie’ set but not used [-Wunused-but-set-variable=]
593 | u8 default_taps_ondie[NUM_TRGMII_CTRL];
| ^~~~~~~~~~~~~~~~~~
Whoops, got it in v2, thank you.
Caleb