net/mlx4_core: Fix smatch error - possible access to a null variable

Fix the "error: we previously assumed 'out_param' could be null" found
by smatch semantic checker on:
drivers/net/ethernet/mellanox/mlx4/cmd.c:506 mlx4_cmd_poll()
drivers/net/ethernet/mellanox/mlx4/cmd.c:578 mlx4_cmd_wait()

Signed-off-by: Eyal Perry <eyalpe@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c
index 2420103..357dcb0 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c
@@ -473,6 +473,13 @@ static int mlx4_cmd_poll(struct mlx4_dev *dev, u64 in_param, u64 *out_param,
                goto out;
        }
 
+       if (out_is_imm && !out_param) {
+               mlx4_err(dev, "response expected while output mailbox is NULL for command 0x%x\n",
+                        op);
+               err = -EINVAL;
+               goto out;
+       }
+
        err = mlx4_cmd_post(dev, in_param, out_param ? *out_param : 0,
                            in_modifier, op_modifier, op, CMD_POLL_TOKEN, 0);
        if (err)
@@ -551,6 +558,13 @@ static int mlx4_cmd_wait(struct mlx4_dev *dev, u64 in_param, u64 *out_param,
        cmd->free_head = context->next;
        spin_unlock(&cmd->context_lock);
 
+       if (out_is_imm && !out_param) {
+               mlx4_err(dev, "response expected while output mailbox is NULL for command 0x%x\n",
+                        op);
+               err = -EINVAL;
+               goto out;
+       }
+
        init_completion(&context->done);
 
        mlx4_cmd_post(dev, in_param, out_param ? *out_param : 0,