Message ID | 4F65F1E8.9000505@mellanox.co.il |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
From: Yevgeny Petrilin <yevgenyp@mellanox.co.il> Date: Sun, 18 Mar 2012 16:32:08 +0200 > From: Eugenia Emantayev <eugenia@mellanox.co.il> > > > Prevent race condition between commands on comm channel. > Happened while unloading the driver when switching from > event to polling mode. VF got completion on the last command > before switching to polling mode, but toggle was not changed. > After the fix - VF will not write the next command before > toggle is updated. > > Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c index eaf09d4..6037d36 100644 --- a/drivers/net/ethernet/mellanox/mlx4/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c @@ -239,6 +239,7 @@ static int mlx4_comm_cmd_wait(struct mlx4_dev *dev, u8 op, { struct mlx4_cmd *cmd = &mlx4_priv(dev)->cmd; struct mlx4_cmd_context *context; + unsigned long end; int err = 0; down(&cmd->event_sem); @@ -268,6 +269,14 @@ static int mlx4_comm_cmd_wait(struct mlx4_dev *dev, u8 op, } out: + /* wait for comm channel ready + * this is necessary for prevention the race + * when switching between event to polling mode + */ + end = msecs_to_jiffies(timeout) + jiffies; + while (comm_pending(dev) && time_before(jiffies, end)) + cond_resched(); + spin_lock(&cmd->context_lock); context->next = cmd->free_head; cmd->free_head = context - cmd->context;