path: root/drivers/infiniband/hw/mlx4
diff options
authorWill Deacon <will.deacon@arm.com>2019-02-22 17:14:59 +0000
committerWill Deacon <will.deacon@arm.com>2019-04-08 12:01:02 +0100
commitfb24ea52f78e0d595852e09e3a55697c8f442189 (patch)
tree00ca29c7b0b8df6258a1ad1faf34f6e838ada26c /drivers/infiniband/hw/mlx4
parentdrivers: Remove useless trailing comments from mmiowb() invocations (diff)
drivers: Remove explicit invocations of mmiowb()
mmiowb() is now implied by spin_unlock() on architectures that require it, so there is no reason to call it from driver code. This patch was generated using coccinelle: @mmiowb@ @@ - mmiowb(); and invoked as: $ for d in drivers include/linux/qed sound; do \ spatch --include-headers --sp-file mmiowb.cocci --dir $d --in-place; done NOTE: mmiowb() has only ever guaranteed ordering in conjunction with spin_unlock(). However, pairing each mmiowb() removal in this patch with the corresponding call to spin_unlock() is not at all trivial, so there is a small chance that this change may regress any drivers incorrectly relying on mmiowb() to order MMIO writes between CPUs using lock-free synchronisation. If you've ended up bisecting to this commit, you can reintroduce the mmiowb() calls using wmb() instead, which should restore the old behaviour on all architectures other than some esoteric ia64 systems. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/infiniband/hw/mlx4')
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index 429a59c5801c..9426936460f8 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -3744,12 +3744,6 @@ out:
to_mdev(ibqp->device)->uar_map + MLX4_SEND_DOORBELL);
- /*
- * Make sure doorbells don't leak out of SQ spinlock
- * and reach the HCA out of order.
- */
- mmiowb();
stamp_send_wqe(qp, ind + qp->sq_spare_wqes - 1);
qp->sq_next_wqe = ind;