Re: [PATCH net-next v7 1/6] dt-bindings: net: Add tx and rx internal delays
From: Dan Murphy
Date: Thu Jun 18 2020 - 09:44:25 EST
Andrew
On 6/17/20 9:01 PM, Andrew Lunn wrote:
On Wed, Jun 17, 2020 at 01:20:14PM -0500, Dan Murphy wrote:
tx-internal-delays and rx-internal-delays are a common setting for RGMII
capable devices.
These properties are used when the phy-mode or phy-controller is set to
rgmii-id, rgmii-rxid or rgmii-txid. These modes indicate to the
controller that the PHY will add the internal delay for the connection.
Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
---
.../devicetree/bindings/net/ethernet-phy.yaml | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
index 9b1f1147ca36..b2887476fe6a 100644
--- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml
+++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
@@ -162,6 +162,17 @@ properties:
description:
Specifies a reference to a node representing a SFP cage.
+
+ rx-internal-delay-ps:
+ description: |
+ RGMII Receive PHY Clock Delay defined in pico seconds. This is used for
+ PHY's that have configurable RX internal delays.
+
+ tx-internal-delay-ps:
+ description: |
+ RGMII Transmit PHY Clock Delay defined in pico seconds. This is used for
+ PHY's that have configurable TX internal delays.
+
So in a later patch you have:
default: 2000
That seems to apply that these values only apply when the phy mode
indicates a delay is needed. It would be good to document that here,
when each of these properties will be used. Also, that they default to
2000 when not present.
The default of 2000ps is for the DP83869 only. The DP83822 fixed delay
is 3500ps.
So indicating that the default here is 2000ps for all devices is not
correct.
But I can add a note that if these properties are present then the delay
is added by the PHY.
Dan
Andrew