net: phy: prefer 1000baseT over 1000baseKX

stable inclusion
from stable-v5.10.94
commit 7e09f9d15e430fd4d3189fc9b243abc5fe42e215
bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7e09f9d15e430fd4d3189fc9b243abc5fe42e215

--------------------------------

[ Upstream commit f20f94f7 ]

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: NTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: NRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reported-by: NFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/E1muvFO-00F6jY-1K@rmk-PC.armlinux.org.ukSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/net/phy/phy-core.c

@@ -161,11 +161,11 @@ static const struct phy_setting settings[] = {
 	PHY_SETTING(   2500, FULL,   2500baseT_Full		),
 	PHY_SETTING(   2500, FULL,   2500baseX_Full		),
 	/* 1G */
-	PHY_SETTING(   1000, FULL,   1000baseKX_Full		),
 	PHY_SETTING(   1000, FULL,   1000baseT_Full		),
 	PHY_SETTING(   1000, HALF,   1000baseT_Half		),
 	PHY_SETTING(   1000, FULL,   1000baseT1_Full		),
 	PHY_SETTING(   1000, FULL,   1000baseX_Full		),
+	PHY_SETTING(   1000, FULL,   1000baseKX_Full		),
 	/* 100M */
 	PHY_SETTING(    100, FULL,    100baseT_Full		),
 	PHY_SETTING(    100, FULL,    100baseT1_Full		),