Re: [PATCH net-next 2/6] ARM: dts: ls1021a-tsn: update RGMII delays for sja1105 switch

From: Florian Fainelli
Date: Fri Oct 15 2021 - 13:16:52 EST


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 not apply delays
> in any direction (mostly because the SJA1105T can't do that, so this
> board uses PCB traces). To preserve that but also silence the driver,
> use explicit delays of 0 ns. The delay information from the phy-mode is
> 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@xxxxxxx>

Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
--
Florian