[PATCH v3 0/7] net: dsa: mt7530: support EcoNet EN751221

[Caleb James DeLisle]

Hello Christian,


Thank you for testing!


On 28/10/2026 17:03, Cristian Papa wrote:
> Hi Caleb,
>
> I tested v3 on a TP-Link Archer XR500v v1 (EN7526G: on-die switch plus the
> MCM gigabit switch).
>
> Setup: OpenWrt with kernel 6.18.44. I took the four mt7530 files from
> econet_eth at 3a8bcd2e6398 (they contain every line added by 1/7, 3/7,
> 4/7, 5/7 and 7/7 of v3) and booted from RAM over TFTP, nothing written to
> flash.
>
> With the DT from en751221g.dtsi in openwrt#25330 (MCM "econet,en751221",
> no "mediatek,mcm", dsa,member <0 1> on the on-die switch and <0 0> on the
> MCM):
>
> - 18/18 boots: all 10 TRGMII lanes found a window, no "calibration
>    failed", "TRGMII inter-switch link initialized", DSA tree set up, ping
>    over lan4.
> - The chosen taps were stable across boots (+/-1): SoC->MCM 15-22,
>    MCM->SoC 27-29. In the SoC->MCM direction the window always starts at
>    tap 0.
> - 6 of those boots ran iperf3 for 6 s each way through lan4: 0 RX CRC
>    errors on on-die port 5 (~1.05M frames) and on MCM port 6 (~1.29M
>    frames). In 4 of 10 boots MCM port 6 already had 1 CRC error before any
>    traffic, probably from the calibration; it did not grow.
>
> Following the binding in 6/7, the MCM does not come up on this board:
>
> - "econet,en751221-gswitch": mt7530-mdio.c in 7/7 still matches
>    "econet,en751221", so nothing probes the MCM and there are no LAN
>    ports.


Whoops, I see I made an error on patch 7 and did not update the name to 
"gswitch", I will send a v4 soon.


> - "mediatek,mcm", which the binding requires for -gswitch: the probe
>    fails with "Couldn't get our reset line", since nothing provides an
>    "mcm" reset yet (the TODO in en751221g.dtsi).


Also expected as setting "mediatek,mcm" requires specifying the reset 
line, and reset for the MCM is on its own unique register and is not yet 
supported by en7523-clk.c reset controller. The OpenWrt implementation 
is a bit cheating by not bumping the reset line at all right now but in 
my testing it was not different when I manually bumped it so it seems 
okay for now


>
> So I think 7/7 should match the new compatible, and the binding should not
> require "mediatek,mcm" while there is no "mcm" reset for the EN751221.
>
> Not covered yet: cold boots, and the other LAN ports beyond link-up on
> lan3/lan4. I'm happy to give a Tested-by once the compatible strings line
> up, and to rerun anything you'd like; the full boot logs are available.


I'll send a v4 and I will synchronize the PR on OpenWrt to it so you can 
test easily.


Thanks,

Caleb


>
> Thanks,
> Cristian