It looks like either the current kernel or the hardware has reliability issues when the gmac is actually running at 1GBit. In my test-case it is not able to boot on a nfsroot at this speed, as the system will always lose the connection to the nfs-server during boot, before reaching any login prompt and not recover from this. So until this is solved, limit the speed to 100MBit as with this the nfsroot survives stress tests like an apt-get upgrade without problems. Signed-off-by: Heiko Stuebner <heiko at sntech.de> --- arch/arm64/boot/dts/rockchip/rk3328-rock64.dts | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts b/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts index d4f80786e7c2..3890468678ce 100644 --- a/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts +++ b/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts @@ -132,6 +132,8 @@ assigned-clocks = <&cru SCLK_MAC2IO>, <&cru SCLK_MAC2IO_EXT>; assigned-clock-parents = <&gmac_clkin>, <&gmac_clkin>; clock_in_out = "input"; + /* shows instability at 1GBit right now */ + max-speed = <100>; phy-supply = <&vcc_io>; phy-mode = "rgmii"; pinctrl-names = "default"; -- 2.14.2