Thread (19 messages) 19 messages, 4 authors, 2021-10-18

Re: [PATCH net-next 1/6] ARM: dts: imx6qp-prtwd3: update RGMII delays for sja1105 switch

From: Florian Fainelli <f.fainelli@gmail.com>
Date: 2021-10-15 17:16:35
Also in: linux-arm-kernel, linux-devicetree, lkml

On 10/13/21 3:23 PM, 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>
-- 
Florian
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