arm64: dts: rockchip: fix rock64 gmac2io stability issues

[ Upstream commit 73e42e18669934fa96cf2bb54291da54177076d7 ]

This commit enables thresh dma mode as this forces to disable checksuming,
and chooses delay values which make the interface stable.

These changes are needed, because ROCK64 is faced with two problems:
1. tx checksuming does not work with packets larger than 1498,
2. the default delays for tx/rx are not stable when using 1Gbps connection.

Delays were found out with:
https://github.com/ayufan-rock64/linux-build/tree/master/recipes/gmac-delays-test

Signed-off-by: Kamil Trzciński <ayufan@ayufan.eu>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts b/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
index d4f80786e7c20c0a46bacb9636f8defc7ef137b4..28257724a56e74b79b83c69a76bea0da4e0fd9ed 100644 (file)
--- a/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
@@ -136,11 +136,12 @@
        phy-mode = "rgmii";
        pinctrl-names = "default";
        pinctrl-0 = <&rgmiim1_pins>;
+       snps,force_thresh_dma_mode;
        snps,reset-gpio = <&gpio1 RK_PC2 GPIO_ACTIVE_LOW>;
        snps,reset-active-low;
        snps,reset-delays-us = <0 10000 50000>;
-       tx_delay = <0x26>;
-       rx_delay = <0x11>;
+       tx_delay = <0x24>;
+       rx_delay = <0x18>;
        status = "okay";
 };