IB/mthca: Update QP state if query QP succeeds

If the QP was moved to another state (such as SQE) by the hardware,
then after this change the user won't have to set the IBV_QP_CUR_STATE
mask in order to execute modify QP in order to recover from this state.

Signed-off-by: Dotan Barak <dotanb@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/mthca/mthca_qp.c

@@ -437,29 +437,34 @@ int mthca_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *qp_attr, int qp_attr_m
 	int mthca_state;
 	u8 status;
 
+	mutex_lock(&qp->mutex);
+
 	if (qp->state == IB_QPS_RESET) {
 		qp_attr->qp_state = IB_QPS_RESET;
 		goto done;
 	}
 
 	mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
-	if (IS_ERR(mailbox))
-		return PTR_ERR(mailbox);
+	if (IS_ERR(mailbox)) {
+		err = PTR_ERR(mailbox);
+		goto out;
+	}
 
 	err = mthca_QUERY_QP(dev, qp->qpn, 0, mailbox, &status);
 	if (err)
-		goto out;
+		goto out_mailbox;
 	if (status) {
 		mthca_warn(dev, "QUERY_QP returned status %02x\n", status);
 		err = -EINVAL;
-		goto out;
+		goto out_mailbox;
 	}
 
 	qp_param    = mailbox->buf;
 	context     = &qp_param->context;
 	mthca_state = be32_to_cpu(context->flags) >> 28;
 
-	qp_attr->qp_state 	     = to_ib_qp_state(mthca_state);
+	qp->state		     = to_ib_qp_state(mthca_state);
+	qp_attr->qp_state	     = qp->state;
 	qp_attr->path_mtu 	     = context->mtu_msgmax >> 5;
 	qp_attr->path_mig_state      =
 		to_ib_mig_state((be32_to_cpu(context->flags) >> 11) & 0x3);
@@ -506,8 +511,11 @@ int mthca_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *qp_attr, int qp_attr_m
 
 	qp_init_attr->cap	     = qp_attr->cap;
 
-out:
+out_mailbox:
 	mthca_free_mailbox(dev, mailbox);
+
+out:
+	mutex_unlock(&qp->mutex);
 	return err;
 }