[PATCH AUTOSEL 5.15 01/29] ARM: dts: imx6qp-prtwd3: update RGMII delays for sja1105 switch

Sasha Levin
2021-12-21T01:57:58Z

From: Vladimir Oltean <vladimir.oltean@nxp.com>

[ Upstream commit f2c2e9ebb2cf476c09e59d073db031fbf7ef4914 ]

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>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 b92e0f2748a51..29dd59bfa73dd 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>;
--
2.34.1