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

IB/rxe: increment msn only when completing a request

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: ib-rxe-increment-msn-only-when-completing-a-request.patch and it can be found in the queue-4.9 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 foo@baz Thu Dec 21 09:02:40 CET 2017

From: David Marchand david.marchand@6wind.com Date: Fri, 24 Feb 2017 15:38:26 +0100 Subject: IB/rxe: increment msn only when completing a request

From: David Marchand david.marchand@6wind.com

[ Upstream commit 9fcd67d1772c43d2f23e8fca56acc7219e991676 ]

According to C9-147, MSN should only be incremented when the last packet of a multi packet request has been received.

"Logically, the requester associates a sequential Send Sequence Number (SSN) with each WQE posted to the send queue. The SSN bears a one- to-one relationship to the MSN returned by the responder in each re- sponse packet. Therefore, when the requester receives a response, it in- terprets the MSN as representing the SSN of the most recent request completed by the responder to determine which send WQE(s) can be completed."

Fixes: 8700e3e7c485 ("Soft RoCE driver")

Signed-off-by: David Marchand david.marchand@6wind.com Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/sw/rxe/rxe_resp.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -799,18 +799,17 @@ static enum resp_states execute(struct r /* Unreachable */ WARN_ON(1);

- /* We successfully processed this new request. */ - qp->resp.msn++; - /* next expected psn, read handles this separately */ qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;

qp->resp.opcode = pkt->opcode; qp->resp.status = IB_WC_SUCCESS;

- if (pkt->mask & RXE_COMP_MASK) + if (pkt->mask & RXE_COMP_MASK) { + /* We successfully processed this new request. */ + qp->resp.msn++; return RESPST_COMPLETE; - else if (qp_type(qp) == IB_QPT_RC) + } else if (qp_type(qp) == IB_QPT_RC) return RESPST_ACKNOWLEDGE; else return RESPST_CLEANUP;

Patches currently in stable-queue which might be from david.marchand@6wind.com are

queue-4.9/ib-rxe-increment-msn-only-when-completing-a-request.patch