linux-kernel - Re: [PATCH] arm64: dts: rockchip: use MAC TX delay for ROCK 4D

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aIJ4lZgfTiNmHaXF@shell.armlinux.org.uk>
Date: Thu, 24 Jul 2025 19:16:53 +0100
From: "Russell King (Oracle)" <linux@...linux.org.uk>
To: Sebastian Reichel <sebastian.reichel@...labora.com>
Cc: Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Heiko Stuebner <heiko@...ech.de>, Andrew Lunn <andrew@...n.ch>,
	devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org, linux-kernel@...r.kernel.org,
	kernel@...labora.com
Subject: Re: [PATCH] arm64: dts: rockchip: use MAC TX delay for ROCK 4D

On Thu, Jul 24, 2025 at 04:31:25PM +0200, Sebastian Reichel wrote:
> According to the Ethernet controller device tree binding "rgmii-id"
> means, that the PCB does not have extra long lines to add the required
> delays. This is indeed the case for the ROCK 4D.
> 
> The problem is, that the Rockchip MAC Linux driver interprets the
> interface type differently and abuses the information to configure
> RX and TX delays in the MAC using (vendor) properties 'rx_delay' and
> 'tx_delay'.
> 
> When Detlev Casanova upstreamed the ROCK 4D device tree, he used the
> correct description for the board ("rgmii-id"). This results in no delays
> being configured in the MAC. At the same time the PHY will provide
> some delays.

So why can't the MAC be fixed to conform to the requirements that are
well documented for RGMII?

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!