From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:43271 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750963AbbEBRSh (ORCPT ); Sat, 2 May 2015 13:18:37 -0400 Subject: Patch "IB/mlx4: Fix WQE LSO segment calculation" has been added to the 4.0-stable tree To: erezsh@mellanox.com, dledford@redhat.com, gregkh@linuxfoundation.org, matt@mellanox.com, ogerlitz@mellanox.com Cc: , From: Date: Sat, 02 May 2015 19:18:01 +0200 Message-ID: <14305870814891@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled IB/mlx4: Fix WQE LSO segment calculation to the 4.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ib-mlx4-fix-wqe-lso-segment-calculation.patch and it can be found in the queue-4.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From ca9b590caa17bcbbea119594992666e96cde9c2f Mon Sep 17 00:00:00 2001 From: Erez Shitrit Date: Thu, 2 Apr 2015 13:39:05 +0300 Subject: IB/mlx4: Fix WQE LSO segment calculation From: Erez Shitrit commit ca9b590caa17bcbbea119594992666e96cde9c2f upstream. The current code decreases from the mss size (which is the gso_size from the kernel skb) the size of the packet headers. It shouldn't do that because the mss that comes from the stack (e.g IPoIB) includes only the tcp payload without the headers. The result is indication to the HW that each packet that the HW sends is smaller than what it could be, and too many packets will be sent for big messages. An easy way to demonstrate one more aspect of the problem is by configuring the ipoib mtu to be less than 2*hlen (2*56) and then run app sending big TCP messages. This will tell the HW to send packets with giant (negative value which under unsigned arithmetics becomes a huge positive one) length and the QP moves to SQE state. Fixes: b832be1e4007 ('IB/mlx4: Add IPoIB LSO support') Reported-by: Matthew Finlay Signed-off-by: Erez Shitrit Signed-off-by: Or Gerlitz Signed-off-by: Doug Ledford Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/hw/mlx4/qp.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/infiniband/hw/mlx4/qp.c +++ b/drivers/infiniband/hw/mlx4/qp.c @@ -2605,8 +2605,7 @@ static int build_lso_seg(struct mlx4_wqe memcpy(wqe->header, wr->wr.ud.header, wr->wr.ud.hlen); - *lso_hdr_sz = cpu_to_be32((wr->wr.ud.mss - wr->wr.ud.hlen) << 16 | - wr->wr.ud.hlen); + *lso_hdr_sz = cpu_to_be32(wr->wr.ud.mss << 16 | wr->wr.ud.hlen); *lso_seg_len = halign; return 0; } Patches currently in stable-queue which might be from erezsh@mellanox.com are queue-4.0/ib-mlx4-fix-wqe-lso-segment-calculation.patch