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From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: "Pali Rohár" <pali@kernel.org>
Cc: "Andrew Lunn" <andrew@lunn.ch>,
	"Gregory Clement" <gregory.clement@bootlin.com>,
	"Sebastian Hesselbarth" <sebastian.hesselbarth@gmail.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Marek Behún" <kabel@kernel.org>,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] arm64: dts: armada-3720-turris-mox: remove mrvl,i2c-fast-mode
Date: Mon, 28 Jun 2021 17:16:20 +0100	[thread overview]
Message-ID: <20210628161620.GB22278@shell.armlinux.org.uk> (raw)
In-Reply-To: <20210628151229.25214-1-pali@kernel.org>

On Mon, Jun 28, 2021 at 05:12:29PM +0200, Pali Rohár wrote:
> Some SFP modules are not detected when i2c-fast-mode is enabled even when
> clock-frequency is already set to 100000. The I2C bus violates the timing
> specifications when run in fast mode. So disable fast mode on Turris Mox.

Yes. SFP module specification is 100kHz max on the I2C bus, which is
often forgotten about until someone runs into a problem.

Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

  reply	other threads:[~2021-06-28 16:16 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-28 12:10 [PATCH] arm64: dts: armada-3720-turris-mox.dts: remove mrvl,i2c-fast-mode Pali Rohár
2021-06-28 13:05 ` Marek Behún
2021-06-28 13:10 ` Marek Behún
2021-06-28 15:12 ` [PATCH v2] arm64: dts: armada-3720-turris-mox: " Pali Rohár
2021-06-28 16:16   ` Russell King (Oracle) [this message]
2021-07-23 12:56   ` Gregory CLEMENT

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