Commit f2980103 authored May 07, 2020 by Kai-Heng Feng Committed by Jeff Kirsher May 22, 2020

e1000e: Disable TSO for buffer overrun workaround

Commit b10effb9 ("e1000e: fix buffer overrun while the I219 is
processing DMA transactions") imposes roughly 30% performance penalty.

The commit log states that "Disabling TSO eliminates performance loss
for TCP traffic without a noticeable impact on CPU performance", so
let's disable TSO by default to regain the loss.

CC: stable <stable@vger.kernel.org>
Fixes: b10effb9 ("e1000e: fix buffer overrun while the I219 is processing DMA transactions")
BugLink: https://bugs.launchpad.net/bugs/1802691


Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

parent 0c80cdbf

drivers/net/ethernet/intel/e1000e/netdev.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -5294,6 +5294,10 @@ static void e1000_watchdog_task(struct work_struct *work)
		/* oops */
		break;
		}
		if (hw->mac.type == e1000_pch_spt) {
		netdev->features &= ~NETIF_F_TSO;
		netdev->features &= ~NETIF_F_TSO6;
		}
		}

		/* enable transmits in the hardware, need to do this

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