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e1000e: fix buffer overrun while the I219 is processing DMA transactions
authorSasha Neftin <sasha.neftin@intel.com>
Sun, 6 Aug 2017 13:49:18 +0000 (16:49 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 30 Nov 2017 08:40:59 +0000 (08:40 +0000)
commit0f478f25d50cb6464678284a13f514fefc16e271
tree2a42b2f706f19297f0f7c9cf40f579c6e31cdaba
parent10d0fd29310387313680b12cb69f7b9e11938c8e
e1000e: fix buffer overrun while the I219 is processing DMA transactions

commit b10effb92e272051dd1ec0d7be56bf9ca85ab927 upstream.

IntelĀ® 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 <sasha.neftin@intel.com>
Reviewed-by: Dima Ruinskiy <dima.ruinskiy@intel.com>
Reviewed-by: Raanan Avargil <raanan.avargil@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/net/ethernet/intel/e1000e/netdev.c