This patch seems rather large and is not at all obvious to me...
What is the actual effect of it? Does it cause a crash? A lock-up?
Data loss?
Is this an actual regression?
John
On Fri, Mar 29, 2013 at 06:45:58PM -0700, Bing Zhao wrote:
> cmd_pending is increased in mwifiex_wait_queue_complete() and
> decreased in mwifiex_complete_cmd() currently.
> If there are two or more commands in the cmd_pending_q the main
> worker thread will pick up next command from cmd_pending_q
> automatically after finishing current command. As a result
> mwifiex_wait_queue_complete() will not be called because
> the command is alreay completed. This leads to a negative
> number in cmd_pending count.
>
> Fix it by increasing cmd_pending when a cmd is queued into
> cmd_pending_q and decreasing when that cmd is recycled. For scan
> commands we don't perform inc/dec operations until it's moved
> from scan_pending_q to cmd_pending_q. This covers both
> synchronous and asynchronous commands.
>
> Cc: <stable@xxxxxxxxxxxxxxx> # 3.8
> Reported-by: Daniel Drake <dsd@xxxxxxxxxx>
> Tested-by: Daniel Drake <dsd@xxxxxxxxxx>
> Tested-by: Marco Cesarano <marco@xxxxxxxxxxx>
> Signed-off-by: Bing Zhao <bzhao@xxxxxxxxxxx>
> ---
> drivers/net/wireless/mwifiex/cmdevt.c | 35 ++++++++++++++++++++--------
> drivers/net/wireless/mwifiex/init.c | 2 +-
> drivers/net/wireless/mwifiex/main.h | 2 +
> drivers/net/wireless/mwifiex/sta_cmdresp.c | 2 +-
> drivers/net/wireless/mwifiex/sta_ioctl.c | 3 --
> drivers/net/wireless/mwifiex/util.c | 1 -
> 6 files changed, 29 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/net/wireless/mwifiex/cmdevt.c b/drivers/net/wireless/mwifiex/cmdevt.c
> index 9a1302b..da469c3 100644
> --- a/drivers/net/wireless/mwifiex/cmdevt.c
> +++ b/drivers/net/wireless/mwifiex/cmdevt.c
> @@ -153,7 +153,7 @@ static int mwifiex_dnld_cmd_to_fw(struct mwifiex_private *priv,
> " or cmd size is 0, not sending\n");
> if (cmd_node->wait_q_enabled)
> adapter->cmd_wait_q.status = -1;
> - mwifiex_insert_cmd_to_free_q(adapter, cmd_node);
> + mwifiex_recycle_cmd_node(adapter, cmd_node);
> return -1;
> }
>
> @@ -167,7 +167,7 @@ static int mwifiex_dnld_cmd_to_fw(struct mwifiex_private *priv,
> "DNLD_CMD: FW in reset state, ignore cmd %#x\n",
> cmd_code);
> mwifiex_complete_cmd(adapter, cmd_node);
> - mwifiex_insert_cmd_to_free_q(adapter, cmd_node);
> + mwifiex_recycle_cmd_node(adapter, cmd_node);
> return -1;
> }
>
> @@ -228,7 +228,7 @@ static int mwifiex_dnld_cmd_to_fw(struct mwifiex_private *priv,
> adapter->cmd_sent = false;
> if (cmd_node->wait_q_enabled)
> adapter->cmd_wait_q.status = -1;
> - mwifiex_insert_cmd_to_free_q(adapter, adapter->curr_cmd);
> + mwifiex_recycle_cmd_node(adapter, adapter->curr_cmd);
>
> spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
> adapter->curr_cmd = NULL;
> @@ -632,6 +632,20 @@ mwifiex_insert_cmd_to_free_q(struct mwifiex_adapter *adapter,
> spin_unlock_irqrestore(&adapter->cmd_free_q_lock, flags);
> }
>
> +/* This function reuses a command node. */
> +void mwifiex_recycle_cmd_node(struct mwifiex_adapter *adapter,
> + struct cmd_ctrl_node *cmd_node)
> +{
> + struct host_cmd_ds_command *host_cmd = (void *)cmd_node->cmd_skb->data;
> +
> + mwifiex_insert_cmd_to_free_q(adapter, cmd_node);
> +
> + atomic_dec(&adapter->cmd_pending);
> + dev_dbg(adapter->dev, "cmd: FREE_CMD: cmd=%#x, cmd_pending=%d\n",
> + le16_to_cpu(host_cmd->command),
> + atomic_read(&adapter->cmd_pending));
> +}
> +
> /*
> * This function queues a command to the command pending queue.
> *
> @@ -673,7 +687,9 @@ mwifiex_insert_cmd_to_pending_q(struct mwifiex_adapter *adapter,
> list_add(&cmd_node->list, &adapter->cmd_pending_q);
> spin_unlock_irqrestore(&adapter->cmd_pending_q_lock, flags);
>
> - dev_dbg(adapter->dev, "cmd: QUEUE_CMD: cmd=%#x is queued\n", command);
> + atomic_inc(&adapter->cmd_pending);
> + dev_dbg(adapter->dev, "cmd: QUEUE_CMD: cmd=%#x, cmd_pending=%d\n",
> + command, atomic_read(&adapter->cmd_pending));
> }
>
> /*
> @@ -783,7 +799,7 @@ int mwifiex_process_cmdresp(struct mwifiex_adapter *adapter)
> if (adapter->curr_cmd->cmd_flag & CMD_F_CANCELED) {
> dev_err(adapter->dev, "CMD_RESP: %#x been canceled\n",
> le16_to_cpu(resp->command));
> - mwifiex_insert_cmd_to_free_q(adapter, adapter->curr_cmd);
> + mwifiex_recycle_cmd_node(adapter, adapter->curr_cmd);
> spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
> adapter->curr_cmd = NULL;
> spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);
> @@ -833,7 +849,7 @@ int mwifiex_process_cmdresp(struct mwifiex_adapter *adapter)
> if (adapter->curr_cmd->wait_q_enabled)
> adapter->cmd_wait_q.status = -1;
>
> - mwifiex_insert_cmd_to_free_q(adapter, adapter->curr_cmd);
> + mwifiex_recycle_cmd_node(adapter, adapter->curr_cmd);
> spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
> adapter->curr_cmd = NULL;
> spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);
> @@ -865,8 +881,7 @@ int mwifiex_process_cmdresp(struct mwifiex_adapter *adapter)
> if (adapter->curr_cmd->wait_q_enabled)
> adapter->cmd_wait_q.status = ret;
>
> - /* Clean up and put current command back to cmd_free_q */
> - mwifiex_insert_cmd_to_free_q(adapter, adapter->curr_cmd);
> + mwifiex_recycle_cmd_node(adapter, adapter->curr_cmd);
>
> spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
> adapter->curr_cmd = NULL;
> @@ -993,7 +1008,7 @@ mwifiex_cancel_all_pending_cmd(struct mwifiex_adapter *adapter)
> mwifiex_complete_cmd(adapter, cmd_node);
> cmd_node->wait_q_enabled = false;
> }
> - mwifiex_insert_cmd_to_free_q(adapter, cmd_node);
> + mwifiex_recycle_cmd_node(adapter, cmd_node);
> spin_lock_irqsave(&adapter->cmd_pending_q_lock, flags);
> }
> spin_unlock_irqrestore(&adapter->cmd_pending_q_lock, flags);
> @@ -1040,7 +1055,7 @@ mwifiex_cancel_pending_ioctl(struct mwifiex_adapter *adapter)
> cmd_node = adapter->curr_cmd;
> cmd_node->wait_q_enabled = false;
> cmd_node->cmd_flag |= CMD_F_CANCELED;
> - mwifiex_insert_cmd_to_free_q(adapter, cmd_node);
> + mwifiex_recycle_cmd_node(adapter, cmd_node);
> mwifiex_complete_cmd(adapter, adapter->curr_cmd);
> adapter->curr_cmd = NULL;
> spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, cmd_flags);
> diff --git a/drivers/net/wireless/mwifiex/init.c b/drivers/net/wireless/mwifiex/init.c
> index daf8801..003c014 100644
> --- a/drivers/net/wireless/mwifiex/init.c
> +++ b/drivers/net/wireless/mwifiex/init.c
> @@ -713,7 +713,7 @@ mwifiex_shutdown_drv(struct mwifiex_adapter *adapter)
> if (adapter->curr_cmd) {
> dev_warn(adapter->dev, "curr_cmd is still in processing\n");
> del_timer(&adapter->cmd_timer);
> - mwifiex_insert_cmd_to_free_q(adapter, adapter->curr_cmd);
> + mwifiex_recycle_cmd_node(adapter, adapter->curr_cmd);
> adapter->curr_cmd = NULL;
> }
>
> diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h
> index cab8a85..fef89fd 100644
> --- a/drivers/net/wireless/mwifiex/main.h
> +++ b/drivers/net/wireless/mwifiex/main.h
> @@ -798,6 +798,8 @@ void mwifiex_cancel_pending_ioctl(struct mwifiex_adapter *adapter);
>
> void mwifiex_insert_cmd_to_free_q(struct mwifiex_adapter *adapter,
> struct cmd_ctrl_node *cmd_node);
> +void mwifiex_recycle_cmd_node(struct mwifiex_adapter *adapter,
> + struct cmd_ctrl_node *cmd_node);
>
> void mwifiex_insert_cmd_to_pending_q(struct mwifiex_adapter *adapter,
> struct cmd_ctrl_node *cmd_node,
> diff --git a/drivers/net/wireless/mwifiex/sta_cmdresp.c b/drivers/net/wireless/mwifiex/sta_cmdresp.c
> index c7dc450..9f990e1 100644
> --- a/drivers/net/wireless/mwifiex/sta_cmdresp.c
> +++ b/drivers/net/wireless/mwifiex/sta_cmdresp.c
> @@ -95,7 +95,7 @@ mwifiex_process_cmdresp_error(struct mwifiex_private *priv,
> break;
> }
> /* Handling errors here */
> - mwifiex_insert_cmd_to_free_q(adapter, adapter->curr_cmd);
> + mwifiex_recycle_cmd_node(adapter, adapter->curr_cmd);
>
> spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
> adapter->curr_cmd = NULL;
> diff --git a/drivers/net/wireless/mwifiex/sta_ioctl.c b/drivers/net/wireless/mwifiex/sta_ioctl.c
> index 8c943b6..e6c9b2a 100644
> --- a/drivers/net/wireless/mwifiex/sta_ioctl.c
> +++ b/drivers/net/wireless/mwifiex/sta_ioctl.c
> @@ -59,9 +59,6 @@ int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter,
> {
> int status;
>
> - dev_dbg(adapter->dev, "cmd pending\n");
> - atomic_inc(&adapter->cmd_pending);
> -
> /* Wait for completion */
> status = wait_event_interruptible(adapter->cmd_wait_q.wait,
> *(cmd_queued->condition));
> diff --git a/drivers/net/wireless/mwifiex/util.c b/drivers/net/wireless/mwifiex/util.c
> index 54667e6..e57ac0d 100644
> --- a/drivers/net/wireless/mwifiex/util.c
> +++ b/drivers/net/wireless/mwifiex/util.c
> @@ -239,7 +239,6 @@ int mwifiex_recv_packet(struct mwifiex_private *priv, struct sk_buff *skb)
> int mwifiex_complete_cmd(struct mwifiex_adapter *adapter,
> struct cmd_ctrl_node *cmd_node)
> {
> - atomic_dec(&adapter->cmd_pending);
> dev_dbg(adapter->dev, "cmd completed: status=%d\n",
> adapter->cmd_wait_q.status);
>
> --
> 1.7.0.2
>
>
--
John W. Linville Someday the world will need a hero, and you
linville@xxxxxxxxxxxxx might be all we have. Be ready.
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