From b10effb92e272051dd1ec0d7be56bf9ca85ab927 Mon Sep 17 00:00:00 2001 From: Sasha Neftin Date: Sun, 6 Aug 2017 16:49:18 +0300 Subject: [PATCH] e1000e: fix buffer overrun while the I219 is processing DMA transactions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Intel® 100/200 Series Chipset platforms reduced the round-trip latency for the LAN Controller DMA accesses, causing in some high performance cases a buffer overrun while the I219 LAN Connected Device is processing the DMA transactions. I219LM and I219V devices can fall into unrecovered Tx hang under very stressfully UDP traffic and multiple reconnection of Ethernet cable. This Tx hang of the LAN Controller is only recovered if the system is rebooted. Slightly slow down DMA access by reducing the number of outstanding requests. This workaround could have an impact on TCP traffic performance on the platform. Disabling TSO eliminates performance loss for TCP traffic without a noticeable impact on CPU performance. Please, refer to I218/I219 specification update: https://www.intel.com/content/www/us/en/embedded/products/networking/ ethernet-connection-i218-family-documentation.html Signed-off-by: Sasha Neftin Reviewed-by: Dima Ruinskiy Reviewed-by: Raanan Avargil Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/e1000e/netdev.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index ee9de35003314e..14b096f3d1da49 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -3021,8 +3021,8 @@ static void e1000_configure_tx(struct e1000_adapter *adapter) hw->mac.ops.config_collision_dist(hw); - /* SPT and CNP Si errata workaround to avoid data corruption */ - if (hw->mac.type >= e1000_pch_spt) { + /* SPT and KBL Si errata workaround to avoid data corruption */ + if (hw->mac.type == e1000_pch_spt) { u32 reg_val; reg_val = er32(IOSFPC); @@ -3030,7 +3030,9 @@ static void e1000_configure_tx(struct e1000_adapter *adapter) ew32(IOSFPC, reg_val); reg_val = er32(TARC(0)); - reg_val |= E1000_TARC0_CB_MULTIQ_3_REQ; + /* SPT and KBL Si errata workaround to avoid Tx hang */ + reg_val &= ~BIT(28); + reg_val |= BIT(29); ew32(TARC(0), reg_val); } }