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From:   Stefan Agner <stefan@agner.ch>
To:     robh+dt@kernel.org, khilman@baylibre.com
Cc:     narmstrong@baylibre.com, jbrunet@baylibre.com,
        martin.blumenstingl@googlemail.com, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        Stefan Agner <stefan@agner.ch>
Subject: [PATCH] arm64: dts: meson: fix PHY deassert timing requirements
Date:   Tue,  1 Dec 2020 01:25:50 +0100
Message-Id: <e4df74aed2a7cff09366e72c87d408f41317907f.1606782187.git.stefan@agner.ch>
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According to the datasheet (Rev. 1.4, page 30) the RTL8211F requires
at least 50ms "for internal circuits settling time" before accessing
the PHY registers. This fixes an issue where the Ethernet link doesn't
come up when using ip link set down/up:
  [   29.360965] meson8b-dwmac ff3f0000.ethernet eth0: Link is Down
  [   34.569012] meson8b-dwmac ff3f0000.ethernet eth0: PHY [0.0:00] driver [RTL8211F Gigabit Ethernet] (irq=31)
  [   34.676732] meson8b-dwmac ff3f0000.ethernet: Failed to reset the dma
  [   34.678874] meson8b-dwmac ff3f0000.ethernet eth0: stmmac_hw_setup: DMA engine initialization failed
  [   34.687850] meson8b-dwmac ff3f0000.ethernet eth0: stmmac_open: Hw setup failed

Fixes: 658e4129bb81 ("arm64: dts: meson: g12b: odroid-n2: add the Ethernet PHY reset line")
Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi
index 6982632ae646..a5652caacb27 100644
--- a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi
@@ -413,7 +413,7 @@ external_phy: ethernet-phy@0 {
 		max-speed = <1000>;
 
 		reset-assert-us = <10000>;
-		reset-deassert-us = <30000>;
+		reset-deassert-us = <50000>;
 		reset-gpios = <&gpio GPIOZ_15 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
 
 		interrupt-parent = <&gpio_intc>;
-- 
2.29.2