From: Mike Marciniszyn <mike.marciniszyn@intel.com>
Date: Wed, 20 Apr 2016 13:05:30 +0000 (-0700)
Subject: IB/hfi1: Fix missing lock/unlock in verbs drain callback
X-Git-Tag: v4.6-rc6~7^2~4
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b9b06cb6feda;p=karo-tx-linux.git

IB/hfi1: Fix missing lock/unlock in verbs drain callback

The iowait_sdma_drained() callback lacked locking to
protect the qp s_flags field.

This causes the s_flags to be out of sync
on multiple CPUs, potentially corrupting the s_flags.

Fixes: a545f5308b6c ("staging/rdma/hfi: fix CQ completion order issue")
Reviewed-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
---

diff --git a/drivers/staging/rdma/hfi1/qp.c b/drivers/staging/rdma/hfi1/qp.c
index 29a5ad28019b..dc9119e1b458 100644
--- a/drivers/staging/rdma/hfi1/qp.c
+++ b/drivers/staging/rdma/hfi1/qp.c
@@ -519,10 +519,12 @@ static void iowait_sdma_drained(struct iowait *wait)
 	 * do the flush work until that QP's
 	 * sdma work has finished.
 	 */
+	spin_lock(&qp->s_lock);
 	if (qp->s_flags & RVT_S_WAIT_DMA) {
 		qp->s_flags &= ~RVT_S_WAIT_DMA;
 		hfi1_schedule_send(qp);
 	}
+	spin_unlock(&qp->s_lock);
 }
 
 /**