This is a note to let you know that I've just added the patch titled net: amd-xgbe: Fix network fluctuations when using 1G BELFUSE SFP to the 4.19-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-fix-network-fluctuations-when-using-1g-.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit a39f68003aa1c8770903a5759d7e0a6824b781a7 Author: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx> Date: Wed Feb 17 00:37:10 2021 +0530 net: amd-xgbe: Fix network fluctuations when using 1G BELFUSE SFP [ Upstream commit 9eab3fdb419916f66a72d1572f68d82cd9b3f963 ] Frequent link up/down events can happen when a Bel Fuse SFP part is connected to the amd-xgbe device. Try to avoid the frequent link issues by resetting the PHY as documented in Bel Fuse SFP datasheets. Fixes: e722ec82374b ("amd-xgbe: Update the BelFuse quirk to support SGMII") 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-phy-v2.c b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c index 1a617d6d2bf86..54753c8a6a9d7 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c @@ -912,6 +912,9 @@ static bool xgbe_phy_belfuse_phy_quirks(struct xgbe_prv_data *pdata) if ((phy_id & 0xfffffff0) != 0x03625d10) return false; + /* Reset PHY - wait for self-clearing reset bit to clear */ + genphy_soft_reset(phy_data->phydev); + /* Disable RGMII mode */ phy_write(phy_data->phydev, 0x18, 0x7007); reg = phy_read(phy_data->phydev, 0x18);