On Tue, Nov 28, 2017 at 11:23:23AM -0800, Jeff Kirsher wrote:

On Tue, 2017-11-28 at 11:18 +0100, Greg KH wrote:

...

On Tue, Nov 28, 2017 at 11:56:41AM +0200, Neftin, Sasha wrote:

...

On 28/11/2017 11:27, gregkh@linuxfoundation.org wrote:

...

This is a note to let you know that I've just added the patch titled

 e1000e: fix buffer overrun while the I219 is processing DMA

transactions

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queu e.git;a=summary

The filename of the patch is: e1000e-fix-buffer-overrun-while-the-i219-is-processing-dma- transactions.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From b10effb92e272051dd1ec0d7be56bf9ca85ab927 Mon Sep 17 00:00:00 2001 From: Sasha Neftin sasha.neftin@intel.com Date: Sun, 6 Aug 2017 16:49:18 +0300 Subject: 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

From: Sasha Neftin sasha.neftin@intel.com

commit b10effb92e272051dd1ec0d7be56bf9ca85ab927 upstream.

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 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 | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)

--- 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 e1 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 e1 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); } }

Patches currently in stable-queue which might be from sasha.neftin@in tel.com are

queue-4.14/e1000e-fix-buffer-overrun-while-the-i219-is-processing- dma-transactions.patch

This is good. To follow of this one we have sent (Jeff sent today) another one, same functionality but more fundamental and clear patch, please, refer to https://patchwork.ozlabs.org/patch/834472/. I believe you can take it too for stable build .

What is the git commit id of the patch in Linus's tree?

You all do know how to properly tag patches to be included automatically in stable releases, right? If so, how come no one does this for this driver?

Sorry Greg, I did not realize the above commit was queued up for stable, which is why the follow on commit that Sasha was referring to was not CC'd to stable mailing list. I do and will usual add the stable mailing list to commits that need to be queued up for the stable trees.

Anyways, here is the commit id for the follow on patch for the changes above. David Miller just accepted it into his net tree this morning, here is the commit id info:

commit c0f4b163a03e73055dd734eaca64b9580e72e7fb Author: Sasha Neftin sasha.neftin@intel.com Date: Mon Nov 6 08:31:59 2017 +0200

e1000e: fix the use of magic numbers for buffer overrun issue

This is a follow on to commit b10effb92e27 ("fix buffer overrun while the I219 is processing DMA transactions") to address David Laights concerns about the use of "magic" numbers. So define masks as well as add additional code comments to give a better understanding of what needs to be done to avoid a buffer overrun. Signed-off-by: Sasha Neftin sasha.neftin@intel.com Reviewed-by: Alexander H Duyck alexander.h.duyck@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

Now added to the 4.14-stable tree, thanks.

greg k-h