Re: [PATCH v1 5/7] ARM i.MX6q: remove Atheros AR8035 SmartEEE fixup
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Date: 2021-02-08 14:44:53
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On Mon, Feb 08, 2021 at 10:20:38AM +0100, Oleksij Rempel wrote:
On Wed, Feb 03, 2021 at 09:56:28AM +0000, Russell King - ARM Linux admin wrote:quoted
That is the historical fix for this problem, but there is a better solution now in net-next - configuring the Tw parameter for gigabit connections. That solves the random link drop issue when EEE is enabled.Do you mean this properties? qca,smarteee-tw-us-1g qca,smarteee-tw-us-100m Do you have some recommendations, which values can be here used? Are they same for all MACs? Or, can we calculate this values automatically?
I don't think there's a way to "calculate" them. The AR8035 default is 17us for 1G and 23us for 100M. Increasing the 1G Tw to 26us or 27us fixes it on several different Solidrun platforms (iMX6 Hummingboards and Cubox-i, and LX2160A based). The boards all have differing layouts, so I don't think it's layout or SoC specific (which is good news.) These figures have been arrived at by repetitive long-term testing and observing whether there are sporadic link drops over these platforms.
Beside, I have seen this patch: "ARM: dts: imx6qdl-sr-som: fix some cubox-i platforms"
That's for a different problem: moving these settings to DT broke some Cubox-i platforms because of the weird ways that the AR8035 configures the address bits, using the LED pin. Tying a LED to the LED pin is not sufficient to guarantee that a board always configures the PHY to a particular address, so it can appear on address 0 or 4 depending on noise, temperature, supply voltage, and PHY chip thresholds. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel