diff mbox series

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

Message ID 20210323140019.14388-1-heiko.thiery@gmail.com
State New
Headers show
Series [v2] arm64: dts: imx8mq-kontron-pitx-imx8m: pass phy reset delays | expand

Commit Message

Heiko Thiery March 23, 2021, 2 p.m. UTC
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@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(+)

Comments

Shawn Guo March 29, 2021, 1:51 a.m. UTC | #1
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 <heiko.thiery@gmail.com>

> ---

> 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
diff mbox series

Patch

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>;
 		};
 	};
 };