This is a note to let you know that I've just added the patch titled net: amd-xgbe: Reset link when the link never comes back to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-amd-xgbe-reset-link-when-the-link-never-comes-ba.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e3437afa558b4dc939b447df0848fe1e64948d76 Author: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx> Date: Wed Feb 17 00:37:09 2021 +0530 net: amd-xgbe: Reset link when the link never comes back [ Upstream commit 84fe68eb67f9499309cffd97c1ba269de125ff14 ] Normally, auto negotiation and reconnect should be automatically done by the hardware. But there seems to be an issue where auto negotiation has to be restarted manually. This happens because of link training and so even though still connected to the partner the link never "comes back". This needs an auto-negotiation restart. Also, a change in xgbe-mdio is needed to get ethtool to recognize the link down and get the link change message. This change is only required in a backplane connection mode. Fixes: abf0a1c2b26a ("amd-xgbe: Add support for SFP+ modules") Co-developed-by: Sudheesh Mavila <sudheesh.mavila@xxxxxxx> Signed-off-by: Sudheesh Mavila <sudheesh.mavila@xxxxxxx> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx> Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c index 4d5506d928973..156a0bc8ab01d 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c @@ -1345,7 +1345,7 @@ static void xgbe_phy_status(struct xgbe_prv_data *pdata) &an_restart); if (an_restart) { xgbe_phy_config_aneg(pdata); - return; + goto adjust_link; } if (pdata->phy.link) { diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c index f024db6d90158..387d3aeebf237 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c @@ -2601,6 +2601,14 @@ static int xgbe_phy_link_status(struct xgbe_prv_data *pdata, int *an_restart) if (reg & MDIO_STAT1_LSTATUS) return 1; + if (pdata->phy.autoneg == AUTONEG_ENABLE && + phy_data->port_mode == XGBE_PORT_MODE_BACKPLANE) { + if (!test_bit(XGBE_LINK_INIT, &pdata->dev_state)) { + netif_carrier_off(pdata->netdev); + *an_restart = 1; + } + } + /* No link, attempt a receiver reset cycle */ if (phy_data->rrc_count++ > XGBE_RRC_FREQUENCY) { phy_data->rrc_count = 0;