[PATCH v2 3/3] arm64: dts: imx8mm-var-dart: increase PHY reset deassert delay

Stefano Radaelli stefano.radaelli21 at gmail.com
Thu Sep 17 08:41:30 PDT 2026


From: Stefano Radaelli <stefano.r at variscite.com>

The Ethernet PHY reset signal also controls the regulators supplying
VDDA2P5 and VDD1P0, so releasing reset restores the PHY's 2.5 V and
1.0 V analog supplies.

The existing 100 ms reset deassertion delay is not sufficient for
reliable PHY detection. The TI DP83867 requires 200 ms of stabilization
after power-up before MDIO register access.

Increase the reset deassertion delay to 200 ms to ensure reliable PHY
detection across repeated boots.

Co-developed-by: Nate Drude <nate.d at variscite.com>
Signed-off-by: Nate Drude <nate.d at variscite.com>
Signed-off-by: Stefano Radaelli <stefano.r at variscite.com>
---
v1->v2:
 - 

 arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
index 953950e55bf9..4d6a79bbb132 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-var-dart.dtsi
@@ -123,7 +123,7 @@ ethphy0: ethernet-phy at 0 {
 			reg = <0>;
 			reset-gpios = <&gpio1 9 GPIO_ACTIVE_LOW>;
 			reset-assert-us = <10000>;
-			reset-deassert-us = <100000>;
+			reset-deassert-us = <200000>;
 			vddio-supply = <&reg_phy_vddio>;
 		};
 	};
-- 
2.47.3




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