path: root/drivers/infiniband/hw/mlx4/qp.c
diff options
authorErez Shitrit <erezsh@mellanox.com>2015-04-02 13:39:05 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-06 21:59:19 +0200
commit2df1c4ea136939b2563fd559a4fae4371a4dbb32 (patch)
treea00d32179129601a78e461a5b2905752c854e4f7 /drivers/infiniband/hw/mlx4/qp.c
parenta849e648dfdc4089e7848eafeb17c86ad22fabcb (diff)
IB/mlx4: Fix WQE LSO segment calculation
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 <matt@mellanox.com> Signed-off-by: Erez Shitrit <erezsh@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/infiniband/hw/mlx4/qp.c')
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index d8f4d1fe8494..8d7cd98c9671 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -2274,8 +2274,7 @@ static int build_lso_seg(struct mlx4_wqe_lso_seg *wqe, struct ib_send_wr *wr,
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;