diff options
| author |   Ralph Campbell <ralph.campbell@qlogic.com> | 2007-07-06 12:48:23 -0700 |
|---|---|---|
| committer |   Roland Dreier <rolandd@cisco.com> | 2007-07-09 20:12:26 -0700 |
| commit | 4fc570bcbe77f823aae183dd824869f79e74cc97 (patch) | |
| tree | 3955946608a973b06db8b7e5b3ec319354a6fa73 /drivers/infiniband/hw/ipath/ipath_ruc.c | |
| parent | IB: Use menuconfig for InfiniBand menu (diff) | |
| download | linux-dev-4fc570bcbe77f823aae183dd824869f79e74cc97.tar.xz linux-dev-4fc570bcbe77f823aae183dd824869f79e74cc97.zip | |
IB/ipath: Add barrier before updating WC head in shared memory
Add a barrier to make sure the CPU doesn't reorder writes to memory,
since user programs can be polling on the head index update and the
entry should be written before that.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband/hw/ipath/ipath_ruc.c')
| -rw-r--r-- | drivers/infiniband/hw/ipath/ipath_ruc.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/ipath/ipath_ruc.c b/drivers/infiniband/hw/ipath/ipath_ruc.c index 854deb56ac02..85256747d8a1 100644 --- a/drivers/infiniband/hw/ipath/ipath_ruc.c +++ b/drivers/infiniband/hw/ipath/ipath_ruc.c @@ -194,6 +194,8 @@ int ipath_get_rwqe(struct ipath_qp *qp, int wr_id_only) ret = 0; goto bail; } + /* Make sure entry is read after head index is read. */ + smp_rmb(); wqe = get_rwqe_ptr(rq, tail); if (++tail >= rq->size) tail = 0; |