Thread (24 messages) 24 messages, 6 authors, 2023-12-18

Re: [PATCH v3 6/9] riscv: dts: starfive: visionfive-v1: Setup ethernet phy

From: Andrew Lunn <andrew@lunn.ch>
Date: 2023-12-17 17:55:39
Also in: linux-clk, linux-devicetree, linux-riscv, lkml, netdev

On Fri, Dec 15, 2023 at 10:40:45PM +0200, Cristian Ciocaltea wrote:
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
miss-behaviour on the GMAC side, but most likely the issue stems from
the Motorcomm PHY.
I suggest you make a similar comment in the .dts file, just to explain
the odd setting.

	Andrew

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help