From 9cba4ebcf374c3772f6eb61f2d065294b2451b49 Mon Sep 17 00:00:00 2001 From: Mohamad Haj Yahia Date: Thu, 30 Jun 2016 17:34:42 +0300 Subject: [PATCH] net/mlx5: Fix potential deadlock in command mode change Call command completion handler in case of timeout when working in interrupts mode. Avoid flushing the commands workqueue after acquiring the semaphores to prevent a potential deadlock. Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters') Signed-off-by: Mohamad Haj Yahia Signed-off-by: Saeed Mahameed Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 79 +++++++++++---------------- 1 file changed, 33 insertions(+), 46 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c index fda43bc..74067f5 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c @@ -710,13 +710,13 @@ static int wait_func(struct mlx5_core_dev *dev, struct mlx5_cmd_work_ent *ent) if (cmd->mode == CMD_MODE_POLLING) { wait_for_completion(&ent->done); - err = ent->ret; - } else { - if (!wait_for_completion_timeout(&ent->done, timeout)) - err = -ETIMEDOUT; - else - err = 0; + } else if (!wait_for_completion_timeout(&ent->done, timeout)) { + ent->ret = -ETIMEDOUT; + mlx5_cmd_comp_handler(dev, 1UL << ent->idx); } + + err = ent->ret; + if (err == -ETIMEDOUT) { mlx5_core_warn(dev, "%s(0x%x) timeout. Will cause a leak of a command resource\n", mlx5_command_str(msg_to_opcode(ent->in)), @@ -774,28 +774,26 @@ static int mlx5_cmd_invoke(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *in, goto out_free; } - if (!callback) { - err = wait_func(dev, ent); - if (err == -ETIMEDOUT) - goto out; - - ds = ent->ts2 - ent->ts1; - op = be16_to_cpu(((struct mlx5_inbox_hdr *)in->first.data)->opcode); - if (op < ARRAY_SIZE(cmd->stats)) { - stats = &cmd->stats[op]; - spin_lock_irq(&stats->lock); - stats->sum += ds; - ++stats->n; - spin_unlock_irq(&stats->lock); - } - mlx5_core_dbg_mask(dev, 1 << MLX5_CMD_TIME, - "fw exec time for %s is %lld nsec\n", - mlx5_command_str(op), ds); - *status = ent->status; - free_cmd(ent); - } + if (callback) + goto out; - return err; + err = wait_func(dev, ent); + if (err == -ETIMEDOUT) + goto out_free; + + ds = ent->ts2 - ent->ts1; + op = be16_to_cpu(((struct mlx5_inbox_hdr *)in->first.data)->opcode); + if (op < ARRAY_SIZE(cmd->stats)) { + stats = &cmd->stats[op]; + spin_lock_irq(&stats->lock); + stats->sum += ds; + ++stats->n; + spin_unlock_irq(&stats->lock); + } + mlx5_core_dbg_mask(dev, 1 << MLX5_CMD_TIME, + "fw exec time for %s is %lld nsec\n", + mlx5_command_str(op), ds); + *status = ent->status; out_free: free_cmd(ent); @@ -1185,41 +1183,30 @@ err_dbg: return err; } -void mlx5_cmd_use_events(struct mlx5_core_dev *dev) +static void mlx5_cmd_change_mod(struct mlx5_core_dev *dev, int mode) { struct mlx5_cmd *cmd = &dev->cmd; int i; for (i = 0; i < cmd->max_reg_cmds; i++) down(&cmd->sem); - down(&cmd->pages_sem); - flush_workqueue(cmd->wq); - - cmd->mode = CMD_MODE_EVENTS; + cmd->mode = mode; up(&cmd->pages_sem); for (i = 0; i < cmd->max_reg_cmds; i++) up(&cmd->sem); } -void mlx5_cmd_use_polling(struct mlx5_core_dev *dev) +void mlx5_cmd_use_events(struct mlx5_core_dev *dev) { - struct mlx5_cmd *cmd = &dev->cmd; - int i; - - for (i = 0; i < cmd->max_reg_cmds; i++) - down(&cmd->sem); - - down(&cmd->pages_sem); - - flush_workqueue(cmd->wq); - cmd->mode = CMD_MODE_POLLING; + mlx5_cmd_change_mod(dev, CMD_MODE_EVENTS); +} - up(&cmd->pages_sem); - for (i = 0; i < cmd->max_reg_cmds; i++) - up(&cmd->sem); +void mlx5_cmd_use_polling(struct mlx5_core_dev *dev) +{ + mlx5_cmd_change_mod(dev, CMD_MODE_POLLING); } static void free_msg(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *msg) -- 2.7.4