| From f57915cfa5b2b14c1cffa2e83c034f55e3f0e70d Mon Sep 17 00:00:00 2001 |
| From: Or Gerlitz <ogerlitz@mellanox.com> |
| Date: Wed, 22 Oct 2014 14:55:49 -0700 |
| Subject: ib_isert: Add max_send_sge=2 minimum for control PDU responses |
| |
| From: Or Gerlitz <ogerlitz@mellanox.com> |
| |
| commit f57915cfa5b2b14c1cffa2e83c034f55e3f0e70d upstream. |
| |
| This patch adds a max_send_sge=2 minimum in isert_conn_setup_qp() |
| to ensure outgoing control PDU responses with tx_desc->num_sge=2 |
| are able to function correctly. |
| |
| This addresses a bug with RDMA hardware using dev_attr.max_sge=3, |
| that in the original code with the ConnectX-2 work-around would |
| result in isert_conn->max_sge=1 being negotiated. |
| |
| Originally reported by Chris with ocrdma driver. |
| |
| Reported-by: Chris Moore <Chris.Moore@emulex.com> |
| Tested-by: Chris Moore <Chris.Moore@emulex.com> |
| Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> |
| Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/infiniband/ulp/isert/ib_isert.c | 7 +++++-- |
| 1 file changed, 5 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/infiniband/ulp/isert/ib_isert.c |
| +++ b/drivers/infiniband/ulp/isert/ib_isert.c |
| @@ -112,9 +112,12 @@ isert_conn_setup_qp(struct isert_conn *i |
| attr.cap.max_recv_wr = ISERT_QP_MAX_RECV_DTOS; |
| /* |
| * FIXME: Use devattr.max_sge - 2 for max_send_sge as |
| - * work-around for RDMA_READ.. |
| + * work-around for RDMA_READs with ConnectX-2. |
| + * |
| + * Also, still make sure to have at least two SGEs for |
| + * outgoing control PDU responses. |
| */ |
| - attr.cap.max_send_sge = device->dev_attr.max_sge - 2; |
| + attr.cap.max_send_sge = max(2, device->dev_attr.max_sge - 2); |
| isert_conn->max_sge = attr.cap.max_send_sge; |
| |
| attr.cap.max_recv_sge = 1; |
