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@xxxxxxxxx>
---
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@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
