From b8258c74b21ff4dc15cb5e2576063df036a3ecf1 Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve Date: Mon, 1 May 2023 13:05:32 -0400 Subject: [PATCH] arm64: dts: imx8mn-var-som: fix PHY detection bug by adding deassert delay commit f161cea5a20f3aeeb637a88ad1705fc2720b4d58 upstream. While testing the ethernet interface on a Variscite symphony carrier board using an imx8mn SOM with an onboard ADIN1300 PHY (EC hardware configuration), the ethernet PHY is not detected. The ADIN1300 datasheet indicate that the "Management interface active (t4)" state is reached at most 5ms after the reset signal is deasserted. The device tree in Variscite custom git repository uses the following property: phy-reset-post-delay = <20>; Add a new MDIO property 'reset-deassert-us' of 20ms to have the same delay inside the ethphy node. Adding this property fixes the problem with the PHY detection. Note that this SOM can also have an Atheros AR8033 PHY. In this case, a 1ms deassert delay is sufficient. Add a comment to that effect. Fixes: ade0176dd8a0 ("arm64: dts: imx8mn-var-som: Add Variscite VAR-SOM-MX8MN System on Module") Signed-off-by: Hugo Villeneuve Signed-off-by: Shawn Guo Signed-off-by: Greg Kroah-Hartman --- arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi index 67072e6c77d5..cbd9d124c80d 100644 --- a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi +++ b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi @@ -98,11 +98,17 @@ mdio { #address-cells = <1>; #size-cells = <0>; - ethphy: ethernet-phy@4 { + ethphy: ethernet-phy@4 { /* AR8033 or ADIN1300 */ compatible = "ethernet-phy-ieee802.3-c22"; reg = <4>; reset-gpios = <&gpio1 9 GPIO_ACTIVE_LOW>; reset-assert-us = <10000>; + /* + * Deassert delay: + * ADIN1300 requires 5ms. + * AR8033 requires 1ms. + */ + reset-deassert-us = <20000>; }; }; }; -- 2.44.0