From: Tim Harvey <tharvey@gateworks.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+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>,
devicetree@vger.kernel.org, imx@lists.linux.dev,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
Tim Harvey <tharvey@gateworks.com>
Subject: [PATCH 3/7] arm64: dts: imx8mm-venice-gw7901: Increase HS400 USDHC clock speed
Date: Mon, 7 Jul 2025 13:16:58 -0700 [thread overview]
Message-ID: <20250707201702.2930066-3-tharvey@gateworks.com> (raw)
In-Reply-To: <20250707201702.2930066-1-tharvey@gateworks.com>
The IMX8M reference manuals indicate in the USDHC Clock generator section
that the clock rate for DDR is 1/2 the input clock therefore HS400 rates
clocked at 200Mhz require a 400Mhz SDHC clock.
This showed about a 1.5x improvement in read performance for the eMMC's
used on the various imx8m{m,n,p}-venice boards.
Fixes: 2b1649a83afc ("arm64: dts: imx: Add i.mx8mm Gateworks gw7901 dts support")
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
arch/arm64/boot/dts/freescale/imx8mm-venice-gw7901.dts | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw7901.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw7901.dts
index d8b67e12f7d7..272c2b223d16 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw7901.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw7901.dts
@@ -833,6 +833,8 @@ &usdhc3 {
pinctrl-0 = <&pinctrl_usdhc3>;
pinctrl-1 = <&pinctrl_usdhc3_100mhz>;
pinctrl-2 = <&pinctrl_usdhc3_200mhz>;
+ assigned-clocks = <&clk IMX8MM_CLK_USDHC3>;
+ assigned-clock-rates = <400000000>;
bus-width = <8>;
non-removable;
status = "okay";
--
2.25.1
next prev parent reply other threads:[~2025-07-07 20:31 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-07 20:16 [PATCH 1/7] arm64: dts: imx8mm-venice-gw700x: Increase HS400 USDHC clock speed Tim Harvey
2025-07-07 20:16 ` [PATCH 2/7] arm64: dts: imx8mp-venice-gw702x: " Tim Harvey
2025-07-07 20:16 ` Tim Harvey [this message]
2025-07-07 20:16 ` [PATCH 4/7] arm64: dts: imx8mm-venice-gw7902: " Tim Harvey
2025-07-07 20:17 ` [PATCH 5/7] arm64: dts: imx8mn-venice-gw7902: " Tim Harvey
2025-07-07 20:17 ` [PATCH 6/7] arm64: dts: imx8mm-venice-gw7903: " Tim Harvey
2025-07-07 20:17 ` [PATCH 7/7] arm64: dts: imx8mm-venice-gw7904: " Tim Harvey
2025-07-11 8:04 ` [PATCH 1/7] arm64: dts: imx8mm-venice-gw700x: " Shawn Guo
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