05ad5d4581
Add 1000BASE-KX interface mode. This 1G backplane ethernet as described in clause 70. Clause 73 autonegotiation is mandatory, and only full duplex operation is supported. Although at the PMA level this interface mode is identical to 1000BASE-X, it uses a different form of in-band autonegation. This justifies a separate interface mode, since the interface mode (along with the MLO_AN_* autonegotiation mode) sets the type of autonegotiation which will be used on a link. This results in more than just electrical differences between the link modes. With regard to 1000BASE-X, 1000BASE-KX holds a similar position to SGMII: same signaling, but different autonegotiation. PCS drivers (which typically handle in-band autonegotiation) may only support 1000BASE-X, and not 1000BASE-KX. Similarly, the phy mode is used to configure serdes phys with phy_set_mode_ext. Due to the different electrical standards (SFI or XFI vs Clause 70), they will likely want to use different configuration. Adding a phy interface mode for 1000BASE-KX helps simplify configuration in these areas. Signed-off-by: Sean Anderson <sean.anderson@seco.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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 Restructured Text 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.