From 6598ed3586a4b1cc79423666e66b9861631a6c7e Mon Sep 17 00:00:00 2001 From: Quentin Schulz Date: Tue, 21 Apr 2026 11:45:05 +0200 Subject: [PATCH] arm64: dts: rockchip: fix Ethernet PHY not found on PX30 Cobra When not passing the PHY ID with an ethernet-phy-idX.Y compatible property, the MDIO bus will attempt to auto-detect the PHY by reading its registers and then probing the appropriate driver. For this to work, the PHY needs to be in a working state. Unfortunately, the net subsystem doesn't control the PHY reset GPIO when attempting to auto-detect the PHY. This means the PHY needs to be in a working state when entering the Linux kernel. This historically has been the case for this device, but only because the bootloader was taking care of initializing the Ethernet controller even when not using it. We're attempting to support the removal of the network stack in the bootloader, which means the Linux kernel will be entered with the PHY still in reset and now Ethernet doesn't work anymore. The devices in the field only ever had a TI DP83825, so let's simply bypass the auto-detection mechanism entirely by passing the appropriate PHY IDs via the compatible. Fixes: bb510ddc9d3e ("arm64: dts: rockchip: add px30-cobra base dtsi and board variants") Signed-off-by: Quentin Schulz Link: https://patch.msgid.link/20260421-px30-eth-phy-v2-1-68c375b120fd@cherry.de Signed-off-by: Heiko Stuebner --- arch/arm64/boot/dts/rockchip/px30-cobra.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/boot/dts/rockchip/px30-cobra.dtsi b/arch/arm64/boot/dts/rockchip/px30-cobra.dtsi index b7e669d8ba4d..add917af5de7 100644 --- a/arch/arm64/boot/dts/rockchip/px30-cobra.dtsi +++ b/arch/arm64/boot/dts/rockchip/px30-cobra.dtsi @@ -397,7 +397,7 @@ &io_domains { &mdio { dp83825: ethernet-phy@0 { - compatible = "ethernet-phy-ieee802.3-c22"; + compatible = "ethernet-phy-id2000.a140"; reg = <0x0>; pinctrl-names = "default"; pinctrl-0 = <&phy_rst>;