net: phy: prefer 1000baseT over 1000baseKX
authorRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Wed, 8 Dec 2021 11:36:30 +0000 (11:36 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jan 2022 10:04:38 +0000 (11:04 +0100)
commit3c2a24aa3412660b63041014864c53a6a5860f15
treea993857e75a079ae888f42ed58902f2b1b940f44
parent0abd3f9903fae6ecf8db3c89a459971fe7925499
net: phy: prefer 1000baseT over 1000baseKX

[ Upstream commit f20f94f7f52c4685c81754f489ffcc72186e8bdb ]

The PHY settings table is supposed to be sorted by descending match
priority - in other words, earlier entries are preferred over later
entries.

The order of 1000baseKX/Full and 1000baseT/Full is such that we
prefer 1000baseKX/Full over 1000baseT/Full, but 1000baseKX/Full is
a lot rarer than 1000baseT/Full, and thus is much less likely to
be preferred.

This causes phylink problems - it means a fixed link specifying a
speed of 1G and full duplex gets an ethtool linkmode of 1000baseKX/Full
rather than 1000baseT/Full as would be expected - and since we offer
userspace a software emulation of a conventional copper PHY, we want
to offer copper modes in preference to anything else. However, we do
still want to allow the rarer modes as well.

Hence, let's reorder these two modes to prefer copper.

Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/E1muvFO-00F6jY-1K@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/net/phy/phy-core.c