iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

riscv: dts: starfive: visionfive-v1: Setup ethernet phy

Browse Source 
The StarFive VisionFive V1 SBC uses a Motorcomm YT8521 PHY supporting
RGMII-ID, but requires manual adjustment of the RX internal delay to
work properly.

The default RX delay provided by the driver is 1.95 ns, which proves to
be too high. Applying a 50% reduction seems to mitigate the issue.

Also note this adjustment is not necessary on BeagleV Starlight SBC,
which uses a Microchip PHY.  Hence, there is no indication of a
misbehaviour on the GMAC side, but most likely the issue stems from
the Motorcomm PHY.

While at it, drop the redundant gpio include, which is already provided
by jh7100-common.dtsi.

Co-developed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
This commit is contained in:
Cristian Ciocaltea 2023-12-20 23:17:41 +02:00 committed by Conor Dooley
parent 6e204aa211
commit e16d3dc0a2
1 changed files with 21 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dts
View File

@ -6,7 +6,6 @@
/dts-v1/;
#include "jh7100-common.dtsi"
#include <dt-bindings/gpio/gpio.h>
/ {
model = "StarFive VisionFive V1";
@ -18,3 +17,24 @@
priority = <224>;
};
};
&gmac {
phy-handle = <&phy>;
};
/*
* The board uses a Motorcomm YT8521 PHY supporting RGMII-ID, but requires
* manual adjustment of the RX internal delay to work properly. The default
* RX delay provided by the driver (1.95ns) is too high, but applying a 50%
* reduction seems to mitigate the issue.
*
* It is worth noting the adjustment is not necessary on BeagleV Starlight SBC,
* which uses a Microchip PHY. Hence, most likely the Motorcomm PHY is the one
* responsible for the misbehaviour, not the GMAC.
*/
&mdio {
phy: ethernet-phy@0 {
reg = <0>;
rx-internal-delay-ps = <900>;
};
};