[PATCH v2] arm64: dts: imx8mq-kontron-pitx-imx8m: pass phy reset delays

Heiko Thiery heiko.thiery at gmail.com
Tue Mar 23 14:00:21 GMT 2021


The TI DP83867 PHY datasheet says:
T1: Post RESET stabilization time == 195us
T3: Hardware configuration pins transition to output drivers == 64us
T4: RESET pulse width == 1us

So with a little overhead set 'reset-assert-us' to 10us (T4) and
'reset-deassert-us' to 280us (T1+T3).

Without these reset delays the board will hang during startup when
bootargs has ip=dhcp set.

Fixes: 1dc7f3d79a1a ("arm64: dts: fsl: add support for Kontron pitx-imx8m board")
Signed-off-by: Heiko Thiery <heiko.thiery at gmail.com>
---
v2:
 - add desciption what issue will be fixed
 - add Fixes tag

 arch/arm64/boot/dts/freescale/imx8mq-kontron-pitx-imx8m.dts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mq-kontron-pitx-imx8m.dts b/arch/arm64/boot/dts/freescale/imx8mq-kontron-pitx-imx8m.dts
index 91a9ceb10305..f593e4ff62e1 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq-kontron-pitx-imx8m.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mq-kontron-pitx-imx8m.dts
@@ -90,6 +90,8 @@ ethphy0: ethernet-phy at 0 {
 			ti,tx-internal-delay = <DP83867_RGMIIDCTL_2_75_NS>;
 			ti,fifo-depth = <DP83867_PHYCR_FIFO_DEPTH_4_B_NIB>;
 			reset-gpios = <&gpio1 11 GPIO_ACTIVE_LOW>;
+			reset-assert-us = <10>;
+			reset-deassert-us = <280>;
 		};
 	};
 };
-- 
2.30.0




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