From daae46643634b0ec9443411128f79a928824d599 Mon Sep 17 00:00:00 2001 From: Cristian Ciocaltea Date: Wed, 20 Dec 2023 23:17:41 +0200 Subject: riscv: dts: starfive: visionfive-v1: Setup ethernet phy The StarFive VisionFive V1 SBC uses a Motorcomm YT8521 PHY supporting RGMII-ID, but requires manual adjustment of the RX internal delay to work properly. The default RX delay provided by the driver is 1.95 ns, which proves to be too high. Applying a 50% reduction seems to mitigate the issue. Also note this adjustment is not necessary on BeagleV Starlight SBC, which uses a Microchip PHY. Hence, there is no indication of a misbehaviour on the GMAC side, but most likely the issue stems from the Motorcomm PHY. While at it, drop the redundant gpio include, which is already provided by jh7100-common.dtsi. Co-developed-by: Emil Renner Berthing Signed-off-by: Emil Renner Berthing Signed-off-by: Cristian Ciocaltea Reviewed-by: Jacob Keller Reviewed-by: Andrew Lunn Reviewed-by: Emil Renner Berthing Signed-off-by: Conor Dooley (cherry picked from commit e16d3dc0a2d7cd7bd673ce08b39a4239aafe0938) Signed-off-by: Emil Renner Berthing --- .../dts/starfive/jh7100-starfive-visionfive-v1.dts | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts b/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts index e82af72f1aaf..692c696e1ab4 100644 --- a/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts +++ b/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts @@ -6,7 +6,6 @@ /dts-v1/; #include "jh7100-common.dtsi" -#include / { model = "StarFive VisionFive V1"; @@ -18,3 +17,24 @@ priority = <224>; }; }; + +&gmac { + phy-handle = <&phy>; +}; + +/* + * The board uses a Motorcomm YT8521 PHY supporting RGMII-ID, but requires + * manual adjustment of the RX internal delay to work properly. The default + * RX delay provided by the driver (1.95ns) is too high, but applying a 50% + * reduction seems to mitigate the issue. + * + * It is worth noting the adjustment is not necessary on BeagleV Starlight SBC, + * which uses a Microchip PHY. Hence, most likely the Motorcomm PHY is the one + * responsible for the misbehaviour, not the GMAC. + */ +&mdio { + phy: ethernet-phy@0 { + reg = <0>; + rx-internal-delay-ps = <900>; + }; +}; -- cgit v1.2.3