[Intel-wired-lan] [PATCH v2 1/1] e1000e: fix buffer overrun while the I219 is processing DMA transactions

[Brown, Aaron F]

> From: Intel-wired-lan [mailto:intel-wired-lan-bounces at osuosl.org] On Behalf
> Of Sasha Neftin
> Sent: Sunday, November 5, 2017 10:32 PM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher at intel.com>; Neftin, Sasha
> <sasha.neftin at intel.com>; intel-wired-lan at lists.osuosl.org; Avargil, Raanan
> <raanan.avargil at intel.com>; Duyck, Alexander H
> <alexander.h.duyck at intel.com>; Ruinskiy, Dima <dima.ruinskiy at intel.com>
> Subject: [Intel-wired-lan] [PATCH v2 1/1] e1000e: fix buffer overrun while the
> I219 is processing DMA transactions
> 
> Description: 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/networki
> ng/
> ethernet-connection-i218-family-documentation.html
> 
> Signed-off-by: Sasha Neftin <sasha.neftin at intel.com>
> Reviewed-by: Alexander H Duyck <alexander.h.duyck at intel.com>
> Reviewed-by: Dima Ruinskiy <dima.ruinskiy at intel.com>
> Reviewed-by: Raanan Avargil <raanan.avargil at intel.com>
> ---
>  drivers/net/ethernet/intel/e1000e/ich8lan.h | 3 ++-
>  drivers/net/ethernet/intel/e1000e/netdev.c  | 9 ++++++---
>  2 files changed, 8 insertions(+), 4 deletions(-)

Tested-by: Aaron Brown <aaron.f.brown at intel.com>