net: lan78xx: Support auto-downshift to 100Mb/s
authorPhil Elwell <phil@raspberrypi.org>
Mon, 26 Nov 2018 19:46:58 +0000 (19:46 +0000)
committerpopcornmix <popcornmix@gmail.com>
Wed, 27 Jan 2021 19:12:56 +0000 (19:12 +0000)
commit8b270f931722640a2acac5b868c614696ff5efc2
tree23c8dac4f921f3df13836eb2a2d3afb1b24efd8b
parentd4d129942a8283b8e62f2fd28078063cd3cc3ea7
net: lan78xx: Support auto-downshift to 100Mb/s

Ethernet cables with faulty or missing pairs (specifically pairs C and
D) allow auto-negotiation to 1000Mbs, but do not support the successful
establishment of a link. Add a DT property, "microchip,downshift-after",
to configure the number of auto-negotiation failures after which it
falls back to 100Mbs. Valid values are 2, 3, 4, 5 and 0, where 0 means
never downshift.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Documentation/devicetree/bindings/net/microchip,lan78xx.txt
drivers/net/phy/microchip.c
include/linux/microchipphy.h