[PATCH] MIPS: Loongson64: dts: fix phy-related definition of LS7A GMAC

From: Icenowy Zheng
Date: Fri Jan 02 2026 - 10:53:14 EST


Currently the LS7A GMAC device tree node lacks a proper phy-handle
property pointing to the PHY node.

In addition, the phy-mode property specifies "rgmii" without any
internal delay information, which means the board trace needs to add 2ns
delay to the RGMII data lines; but that isn't known to happen on any
Loongson board. The ACPI-based initialization codepath, which is used on
LoongArch-based 3A5000 + 7A1000 hardwares, specifies "rgmii-id" phy
mode, which should be the one we are using.

Add the lacking phy-handle property and set proper phy-mode.

Tested on a LS3A4000_7A1000_NUC_BOARD_V2.1 board with YT8521S PHY.

Signed-off-by: Icenowy Zheng <zhengxingda@xxxxxxxxxxx>
---
arch/mips/boot/dts/loongson/ls7a-pch.dtsi | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/mips/boot/dts/loongson/ls7a-pch.dtsi b/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
index ee71045883e7e..6dee85909f5a6 100644
--- a/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
+++ b/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
@@ -199,7 +199,8 @@ gmac@3,0 {
<13 IRQ_TYPE_LEVEL_HIGH>;
interrupt-names = "macirq", "eth_lpi";
interrupt-parent = <&pic>;
- phy-mode = "rgmii";
+ phy-mode = "rgmii-id";
+ phy-handle = <&phy0>;
mdio {
#address-cells = <1>;
#size-cells = <0>;
@@ -222,7 +223,8 @@ gmac@3,1 {
<15 IRQ_TYPE_LEVEL_HIGH>;
interrupt-names = "macirq", "eth_lpi";
interrupt-parent = <&pic>;
- phy-mode = "rgmii";
+ phy-mode = "rgmii-id";
+ phy-handle = <&phy1>;
mdio {
#address-cells = <1>;
#size-cells = <0>;
--
2.52.0