Andrew Lunn c360eb0c3c dt-bindings: net: ethernet-controller: Add informative text about RGMII delays
Device Tree and Ethernet MAC driver writers often misunderstand RGMII
delays. Rewrite the Normative section in terms of the PCB, is the PCB
adding the 2ns delay. This meaning was previous implied by the
definition, but often wrongly interpreted due to the ambiguous wording
and looking at the definition from the wrong perspective. The new
definition concentrates clearly on the hardware, and should be less
ambiguous.

Add an Informative section to the end of the binding describing in
detail what the four RGMII delays mean. This expands on just the PCB
meaning, adding in the implications for the MAC and PHY.

Additionally, when the MAC or PHY needs to add a delay, which is
software configuration, describe how Linux does this, in the hope of
reducing errors. Make it clear other users of device tree binding may
implement the software configuration in other ways while still
conforming to the binding.

Fixes: 9d3de3c583 ("dt-bindings: net: Add YAML schemas for the generic Ethernet options")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20250430-v6-15-rc3-net-rgmii-delays-v2-1-099ae651d5e5@lunn.ch
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-05 16:49:18 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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