[PATCH v2] arm64: dts: rockchip: Adjust RGMII TXD/RXD delays for the Rock Pi E

From: Adrian Kossmann

Date: Fri Dec 12 2025 - 17:02:27 EST


Current RGMII TXD/RXD delay results in link instability
under load, with throughput eventually dropping to zero.
Adjust the RGMII TXD/RXD delay values for stable link
under load and stable Gigabit throughput

Signed-off-by: Adrian Kossmann <adrian.kossmann@xxxxxxxxx>
---
Changes in v2:
- Changed the patch subject as the last one contained
incorrect changes
- Drop incorrect PHY compatible string change from v1
- Adjustments to RGMII RX/TX delay values
- Link to v1: https://lore.kernel.org/linux-rockchip/20251209210658.458506-2-adrian.kossmann@xxxxxxxxx/

arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e.dts | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e.dts b/arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e.dts
index a4bdd87d0729..29ff0b8b8f18 100644
--- a/arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e.dts
@@ -153,8 +153,8 @@ &gmac2io {
phy-supply = <&vcc_io>;
pinctrl-names = "default";
pinctrl-0 = <&rgmiim1_pins>;
- tx_delay = <0x26>;
- rx_delay = <0x11>;
+ tx_delay = <0x1a>;
+ rx_delay = <0x14>;
status = "okay";

mdio {
--
2.52.0