Re: [PATCH devicetree 1/3] ARM: dts: imx6qp-prtwd3: update RGMII delays for sja1105 switch
From: Oleksij Rempel <o.rempel@pengutronix.de>
Date: 2021-10-20 12:14:14
Also in:
linux-arm-kernel, linux-devicetree, lkml
On Wed, Oct 20, 2021 at 02:36:11PM +0300, Vladimir Oltean wrote:
In the new behavior, the sja1105 driver expects there to be explicit
RGMII delays present on the fixed-link ports, otherwise it will complain
that it falls back to legacy behavior, which is to apply RGMII delays
incorrectly derived from the phy-mode string.
In this case, the legacy behavior of the driver is to apply both RX and
TX delays. To preserve that, add explicit 2 nanosecond delays, which are
identical with what the driver used to add (a 90 degree phase shift).
The delays from the phy-mode are ignored by new kernels (it's still
RGMII as long as it's "rgmii*" something), and the explicit
{rx,tx}-internal-delay-ps properties are ignored by old kernels, so the
change works both ways.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
quoted hunk ↗ jump to hunk
--- arch/arm/boot/dts/imx6qp-prtwd3.dts | 2 ++ 1 file changed, 2 insertions(+)diff --git a/arch/arm/boot/dts/imx6qp-prtwd3.dts b/arch/arm/boot/dts/imx6qp-prtwd3.dts index 7648e8a02000..cf6571cc4682 100644 --- a/arch/arm/boot/dts/imx6qp-prtwd3.dts +++ b/arch/arm/boot/dts/imx6qp-prtwd3.dts@@ -178,6 +178,8 @@ port@4 { label = "cpu"; ethernet = <&fec>; phy-mode = "rgmii-id"; + rx-internal-delay-ps = <2000>; + tx-internal-delay-ps = <2000>; fixed-link { speed = <100>;-- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
-- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |