[PATCH 5.10 113/142] igc: fix link speed advertising

Greg Kroah-Hartman
2021-02-02T19:34:12Z

From: Corinna Vinschen <vinschen@redhat.com>

[ Upstream commit 329a3678ec69962aa67c91397efbd46d36635f91 ]

Link speed advertising in igc has two problems:

- When setting the advertisement via ethtool, the link speed is converted
to the legacy 32 bit representation for the intel PHY code.
This inadvertently drops ETHTOOL_LINK_MODE_2500baseT_Full_BIT (being
beyond bit 31). As a result, any call to `ethtool -s ...' drops the
2500Mbit/s link speed from the PHY settings. Only reloading the driver
alleviates that problem.

Fix this by converting the ETHTOOL_LINK_MODE_2500baseT_Full_BIT to the
Intel PHY ADVERTISE_2500_FULL bit explicitly.

- Rather than checking the actual PHY setting, the .get_link_ksettings
function always fills link_modes.advertising with all link speeds
the device is capable of.

Fix this by checking the PHY autoneg_advertised settings and report
only the actually advertised speeds up to ethtool.

Fixes: 8c5ad0dae93c ("igc: Add ethtool support")
Signed-off-by: Corinna Vinschen <vinschen@redhat.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/igc/igc_ethtool.c | 24 +++++++++++++++-----
1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 61d331ce38cdd..831f2f09de5fb 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1675,12 +1675,18 @@ static int igc_ethtool_get_link_ksettings(struct net_device *netdev,
cmd->base.phy_address = hw->phy.addr;

/* advertising link modes */
- ethtool_link_ksettings_add_link_mode(cmd, advertising, 10baseT_Half);
- ethtool_link_ksettings_add_link_mode(cmd, advertising, 10baseT_Full);
- ethtool_link_ksettings_add_link_mode(cmd, advertising, 100baseT_Half);
- ethtool_link_ksettings_add_link_mode(cmd, advertising, 100baseT_Full);
- ethtool_link_ksettings_add_link_mode(cmd, advertising, 1000baseT_Full);
- ethtool_link_ksettings_add_link_mode(cmd, advertising, 2500baseT_Full);
+ if (hw->phy.autoneg_advertised & ADVERTISE_10_HALF)
+ ethtool_link_ksettings_add_link_mode(cmd, advertising, 10baseT_Half);
+ if (hw->phy.autoneg_advertised & ADVERTISE_10_FULL)
+ ethtool_link_ksettings_add_link_mode(cmd, advertising, 10baseT_Full);
+ if (hw->phy.autoneg_advertised & ADVERTISE_100_HALF)
+ ethtool_link_ksettings_add_link_mode(cmd, advertising, 100baseT_Half);
+ if (hw->phy.autoneg_advertised & ADVERTISE_100_FULL)
+ ethtool_link_ksettings_add_link_mode(cmd, advertising, 100baseT_Full);
+ if (hw->phy.autoneg_advertised & ADVERTISE_1000_FULL)
+ ethtool_link_ksettings_add_link_mode(cmd, advertising, 1000baseT_Full);
+ if (hw->phy.autoneg_advertised & ADVERTISE_2500_FULL)
+ ethtool_link_ksettings_add_link_mode(cmd, advertising, 2500baseT_Full);

/* set autoneg settings */
if (hw->mac.autoneg == 1) {
@@ -1792,6 +1798,12 @@ igc_ethtool_set_link_ksettings(struct net_device *netdev,

ethtool_convert_link_mode_to_legacy_u32(&advertising,
cmd->link_modes.advertising);
+ /* Converting to legacy u32 drops ETHTOOL_LINK_MODE_2500baseT_Full_BIT.
+ * We have to check this and convert it to ADVERTISE_2500_FULL
+ * (aka ETHTOOL_LINK_MODE_2500baseX_Full_BIT) explicitly.
+ */
+ if (ethtool_link_ksettings_test_link_mode(cmd, advertising, 2500baseT_Full))
+ advertising |= ADVERTISE_2500_FULL;

if (cmd->base.autoneg == AUTONEG_ENABLE) {
hw->mac.autoneg = 1;
--
2.27.0