2021-03-24 01:58:45

by Heiko Thiery

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

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 <[email protected]>
---
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

2021-03-29 01:55:30

by Shawn Guo

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

On Tue, Mar 23, 2021 at 03:00:21PM +0100, Heiko Thiery wrote:
> 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 <[email protected]>
> ---
> v2:
> - add desciption what issue will be fixed
> - add Fixes tag

My branch is not a stable one, so I just squashed it into the original
commit.

Shawn