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From:   Heiko Thiery <heiko.thiery@gmail.com>
To:     devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Cc:     Rob Herring <robh+dt@kernel.org>, Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Michael Walle <michael@walle.cc>,
        Heiko Thiery <heiko.thiery@gmail.com>
Subject: [PATCH v2] arm64: dts: imx8mq-kontron-pitx-imx8m: pass phy reset delays
Date:   Tue, 23 Mar 2021 15:00:21 +0100
Message-Id: <20210323140019.14388-1-heiko.thiery@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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(+)

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