[PATCH 2/2] net, mellanox mlx4 Fix compile warnings [v4]

[Prarit Bhargava <prarit@redhat.com>]

Fix unitialized variable warnings.

drivers/net/ethernet/mellanox/mlx4/resource_tracker.c: In function ‘mlx4_HW2SW_CQ_wrapper’:
drivers/net/ethernet/mellanox/mlx4/resource_tracker.c:2551:16: error: ‘cq’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  atomic_dec(&cq->mtt->ref_count);
                ^
drivers/net/ethernet/mellanox/mlx4/resource_tracker.c: In function ‘mlx4_HW2SW_SRQ_wrapper’:
drivers/net/ethernet/mellanox/mlx4/resource_tracker.c:2734:17: error: ‘srq’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  atomic_dec(&srq->mtt->ref_count);

[v2]: davem suggested making cq_res_start_move_to() return 'cq' as an error
pointer instead of setting 'cq' by reference.  I also did the same for
srq.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: dledford@redhat.com
Cc: amirv@mellanox.com
Cc: davem@davemloft.net
Cc: ogerlitz@mellanox.com
Cc: jackm@dev.mellanox.co.il
---
 .../net/ethernet/mellanox/mlx4/resource_tracker.c  |   46 ++++++++++----------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
index dd68763..343206b 100644
--- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
+++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
@@ -1073,8 +1073,9 @@ static int eq_res_start_move_to(struct mlx4_dev *dev, int slave, int index,
 	return err;
 }
 
-static int cq_res_start_move_to(struct mlx4_dev *dev, int slave, int cqn,
-				enum res_cq_states state, struct res_cq **cq)
+static struct res_cq *cq_res_start_move_to(struct mlx4_dev *dev,
+						  int slave, int cqn,
+						  enum res_cq_states state)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct mlx4_resource_tracker *tracker = &priv->mfunc.master.res_tracker;
@@ -1117,18 +1118,19 @@ static int cq_res_start_move_to(struct mlx4_dev *dev, int slave, int cqn,
 			r->com.from_state = r->com.state;
 			r->com.to_state = state;
 			r->com.state = RES_CQ_BUSY;
-			if (cq)
-				*cq = r;
+		} else {
+			r = ERR_PTR(err);
 		}
 	}
 
 	spin_unlock_irq(mlx4_tlock(dev));
 
-	return err;
+	return r;
 }
 
-static int srq_res_start_move_to(struct mlx4_dev *dev, int slave, int index,
-				 enum res_cq_states state, struct res_srq **srq)
+static struct res_srq *srq_res_start_move_to(struct mlx4_dev *dev, int slave,
+					     int index,
+					     enum res_cq_states state)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct mlx4_resource_tracker *tracker = &priv->mfunc.master.res_tracker;
@@ -1167,14 +1169,14 @@ static int srq_res_start_move_to(struct mlx4_dev *dev, int slave, int index,
 			r->com.from_state = r->com.state;
 			r->com.to_state = state;
 			r->com.state = RES_SRQ_BUSY;
-			if (srq)
-				*srq = r;
+		} else {
+			r = ERR_PTR(err);
 		}
 	}
 
 	spin_unlock_irq(mlx4_tlock(dev));
 
-	return err;
+	return r;
 }
 
 static void res_abort_move(struct mlx4_dev *dev, int slave,
@@ -2530,9 +2532,9 @@ int mlx4_SW2HW_CQ_wrapper(struct mlx4_dev *dev, int slave,
 	struct res_cq *cq;
 	struct res_mtt *mtt;
 
-	err = cq_res_start_move_to(dev, slave, cqn, RES_CQ_HW, &cq);
-	if (err)
-		return err;
+	cq = cq_res_start_move_to(dev, slave, cqn, RES_CQ_HW);
+	if (IS_ERR(cq))
+		return PTR_ERR(cq);
 	err = get_res(dev, slave, mtt_base, RES_MTT, &mtt);
 	if (err)
 		goto out_move;
@@ -2565,9 +2567,9 @@ int mlx4_HW2SW_CQ_wrapper(struct mlx4_dev *dev, int slave,
 	int cqn = vhcr->in_modifier;
 	struct res_cq *cq;
 
-	err = cq_res_start_move_to(dev, slave, cqn, RES_CQ_ALLOCATED, &cq);
-	if (err)
-		return err;
+	cq = cq_res_start_move_to(dev, slave, cqn, RES_CQ_ALLOCATED);
+	if (IS_ERR(cq))
+		return PTR_ERR(cq);
 	err = mlx4_DMA_wrapper(dev, slave, vhcr, inbox, outbox, cmd);
 	if (err)
 		goto out_move;
@@ -2709,9 +2711,9 @@ int mlx4_SW2HW_SRQ_wrapper(struct mlx4_dev *dev, int slave,
 	if (srqn != (be32_to_cpu(srqc->state_logsize_srqn) & 0xffffff))
 		return -EINVAL;
 
-	err = srq_res_start_move_to(dev, slave, srqn, RES_SRQ_HW, &srq);
-	if (err)
-		return err;
+	srq = srq_res_start_move_to(dev, slave, srqn, RES_SRQ_ALLOCATED);
+	if (IS_ERR(srq))
+		return PTR_ERR(srq);
 	err = get_res(dev, slave, mtt_base, RES_MTT, &mtt);
 	if (err)
 		goto ex_abort;
@@ -2748,9 +2750,9 @@ int mlx4_HW2SW_SRQ_wrapper(struct mlx4_dev *dev, int slave,
 	int srqn = vhcr->in_modifier;
 	struct res_srq *srq;
 
-	err = srq_res_start_move_to(dev, slave, srqn, RES_SRQ_ALLOCATED, &srq);
-	if (err)
-		return err;
+	srq = srq_res_start_move_to(dev, slave, srqn, RES_SRQ_ALLOCATED);
+	if (IS_ERR(srq))
+		return PTR_ERR(srq);
 	err = mlx4_DMA_wrapper(dev, slave, vhcr, inbox, outbox, cmd);
 	if (err)
 		goto ex_abort;
-- 
1.7.9.3