[PATCH] imx8mn-var-som: dts: fix PHY detection bug by adding deassert delay

From: Hugo Villeneuve
Date: Thu Apr 27 2023 - 16:21:12 EST


From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>

While testing the ethernet interface on a symphony carrier
board using an imx8mn SOM with an onboard PHY (EC hardware
configuration), the ethernet PHY is not detected.

The device tree in Variscite custom linux git repository uses the
following property:

phy-reset-post-delay = <20>;

Add a new property 'reset-deassert-us' of 20ms to have the same delay
inside the ethphy phandle.

Adding this property fixes the problem with the PHY detection.

Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
---
arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
index 67072e6c77d5..9052b0d4b5b4 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
@@ -103,6 +103,7 @@ ethphy: ethernet-phy@4 {
reg = <4>;
reset-gpios = <&gpio1 9 GPIO_ACTIVE_LOW>;
reset-assert-us = <10000>;
+ reset-deassert-us = <20000>;
};
};
};
--
2.30.2