diff options
| author | Mike Marciniszyn <mike.marciniszyn@intel.com> | 2017-08-22 04:26:20 +0300 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2017-08-29 02:12:16 +0300 |
| commit | 5b0ef650bd0f820e922fcc42f1985d4621ae19cf (patch) | |
| tree | 834d5c89337244dc39c868e2cb41fe2fc4e63bcb /drivers/infiniband/hw/qib | |
| parent | 3aaee8ab47a2485ad53c0a2d94945f0105d9feab (diff) | |
| download | linux-5b0ef650bd0f820e922fcc42f1985d4621ae19cf.tar.xz | |
IB/{qib, hfi1}: Avoid flow control testing for RDMA write operation
Section 9.7.7.2.5 of the 1.3 IBTA spec clearly says that receive
credits should never apply to RDMA write.
qib and hfi1 were doing that. The following situation will result
in a QP hang:
- A prior SEND or RDMA_WRITE with immmediate consumed the last
credit for a QP using RC receive buffer credits
- The prior op is acked so there are no more acks
- The peer ULP fails to post receive for some reason
- An RDMA write sees that the credits are exhausted and waits
- The peer ULP posts receive buffers
- The ULP posts a send or RDMA write that will be hung
The fix is to avoid the credit test for the RDMA write operation.
Cc: <stable@vger.kernel.org>
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/hw/qib')
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_rc.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/infiniband/hw/qib/qib_rc.c b/drivers/infiniband/hw/qib/qib_rc.c index 4ddbcac5eabe..e9a91736b12d 100644 --- a/drivers/infiniband/hw/qib/qib_rc.c +++ b/drivers/infiniband/hw/qib/qib_rc.c @@ -348,7 +348,7 @@ int qib_make_rc_req(struct rvt_qp *qp, unsigned long *flags) case IB_WR_RDMA_WRITE: if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) qp->s_lsn++; - /* FALLTHROUGH */ + goto no_flow_control; case IB_WR_RDMA_WRITE_WITH_IMM: /* If no credit, return. */ if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) && @@ -356,7 +356,7 @@ int qib_make_rc_req(struct rvt_qp *qp, unsigned long *flags) qp->s_flags |= RVT_S_WAIT_SSN_CREDIT; goto bail; } - +no_flow_control: ohdr->u.rc.reth.vaddr = cpu_to_be64(wqe->rdma_wr.remote_addr); ohdr->u.rc.reth.rkey = |