Received-SPF: pass (google.com: domain of linux-kernel+bounces-1637-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
From: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
To: "David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Paolo Abeni <pabeni@redhat.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Emil Renner Berthing <kernel@esmil.dk>,
	Samin Guo <samin.guo@starfivetech.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Hal Feng <hal.feng@starfivetech.com>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Richard Cochran <richardcochran@gmail.com>,
	Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: netdev@vger.kernel.org,
	devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-riscv@lists.infradead.org,
	linux-clk@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	kernel@collabora.com,
	Emil Renner Berthing <emil.renner.berthing@canonical.com>
Subject: [PATCH v3 6/9] riscv: dts: starfive: visionfive-v1: Setup ethernet phy
Date: Fri, 15 Dec 2023 22:40:45 +0200
Message-ID: <20231215204050.2296404-7-cristian.ciocaltea@collabora.com>
In-Reply-To: <20231215204050.2296404-1-cristian.ciocaltea@collabora.com>
References: <20231215204050.2296404-1-cristian.ciocaltea@collabora.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

The StarFive VisionFive V1 SBC uses a Motorcomm YT8521 PHY supporting
RGMII-ID, but requires manual adjustment of the RX internal delay to
work properly.

The default RX delay provided by the driver is 1.95 ns, which proves to
be too high. Applying a 50% reduction seems to mitigate the issue.

Also note this adjustment is not necessary on BeagleV Starlight SBC,
which uses a Microchip PHY.  Hence, there is no indication of a
miss-behaviour on the GMAC side, but most likely the issue stems from
the Motorcomm PHY.

Co-developed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 .../boot/dts/starfive/jh7100-starfive-visionfive-v1.dts    | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts b/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts
index e82af72f1aaf..ca134b9f11bf 100644
--- a/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts
+++ b/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts
@@ -18,3 +18,10 @@ gpio-restart {
 		priority = <224>;
 	};
 };
+
+&mdio {
+	phy: ethernet-phy@0 {
+		reg = <0>;
+		rx-internal-delay-ps = <900>;
+	};
+};
-- 
2.43.0