mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-03-01 14:52:13 -05:00
986a7fa4b4
In industrial environments where 10BaseT1L PHYs are replacing existing field bus systems like CAN, it's often essential to retain the existing cable infrastructure. After installation, collecting metrics such as cable length is crucial for assessing the quality of the infrastructure. Traditionally, TDR (Time Domain Reflectometry) is used for this purpose. However, TDR requires interrupting the link, and if the link partner remains active, the TDR measurement will fail. Unlike multi-pair systems, where TDR can be attempted during the MDI-X switching window, 10BaseT1L systems face greater challenges. The TDR sequence on 10BaseT1L is longer and coincides with uninterrupted autonegotiation pulses, making TDR impossible when the link partner is active. The DP83TD510 PHY provides an alternative through ALCD (Active Link Cable Diagnostics), which allows for cable length measurement without disrupting an active link. Since a live link indicates no short or open cable states, ALCD can be used effectively to gather cable length information. Enhance the dp83td510 driver by: - Leveraging ALCD to measure cable length when the link is active. - Bypassing TDR when a link is detected, as ALCD provides the required information without disruption. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://patch.msgid.link/20240822120703.1393130-4-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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.