Re: [PATCH] IB/mlx4: avoid a -Wmaybe-uninitialize warning

[Yishai Hadas]

On 10/25/2016 7:16 PM, Arnd Bergmann wrote:

There is an old warning about mlx4_SW2HW_EQ_wrapper on x86:

ethernet/mellanox/mlx4/resource_tracker.c: In function ‘mlx4_SW2HW_EQ_wrapper’:
ethernet/mellanox/mlx4/resource_tracker.c:3071:10: error: ‘eq’ may be used 
uninitialized in this function [-Werror=maybe-uninitialized]

The problem here is that gcc won't track the state of the variable
across a spin_unlock. Moving the assignment out of the lock is
safe here and avoids the warning.

Signed-off-by: Arnd Bergmann <a...@arndb.de>

Reviewed-by: Yishai Hadas <yish...@mellanox.com>

---
 drivers/net/ethernet/mellanox/mlx4/resource_tracker.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c 
b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
index 84d7857ccc27..c548beaaf910 100644
--- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
+++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
@@ -1605,13 +1605,14 @@ static int eq_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_EQ_BUSY;
-                       if (eq)
-                               *eq = r;
                }
        }

        spin_unlock_irq(mlx4_tlock(dev));

+       if (!err && eq)
+               *eq = r;
+
        return err;
 }