2013-03-16 01:47:38

by Bing Zhao

[permalink] [raw]
Subject: [PATCH 3.9 0/3] mwifiex: patchset to fix cmd timeout on XO-4

This patch series fixes command timeout issue reproduced on XO-4
with SD8787 during driver load/unload tests.

The cmd_pending leak will be addressed separately.

Amitkumar Karwar (1):
mwifiex: fix race when queuing commands

Bing Zhao (2):
mwifiex: skip pending commands after function shutdown
mwifiex: cancel cmd timer and free curr_cmd in shutdown process

drivers/net/wireless/mwifiex/cmdevt.c | 22 ++++++++++++++++------
drivers/net/wireless/mwifiex/init.c | 8 ++++++++
drivers/net/wireless/mwifiex/main.h | 4 ++--
drivers/net/wireless/mwifiex/scan.c | 8 ++++----
drivers/net/wireless/mwifiex/sta_ioctl.c | 10 ++--------
5 files changed, 32 insertions(+), 20 deletions(-)



2013-03-16 01:48:33

by Bing Zhao

[permalink] [raw]
Subject: [PATCH 3.9 1/3] mwifiex: fix race when queuing commands

From: Amitkumar Karwar <[email protected]>

Running the following script repeatedly on XO-4 with SD8787
produces command timeout and system lockup.

insmod mwifiex_sdio.ko
sleep 1
ifconfig eth0 up
iwlist eth0 scan &
sleep 0.5
rmmod mwifiex_sdio

mwifiex_send_cmd_async() is called for sync as well as async
commands. (mwifiex_send_cmd_sync() internally calls it for
sync command.)

"adapter->cmd_queued" gets filled inside mwifiex_send_cmd_async()
routine for both types of commands. But it is used only for sync
commands in mwifiex_wait_queue_complete(). This could lead to a
race when two threads try to queue a sync command with another
sync/async command simultaneously.

Get rid of global variable and pass command node as a parameter
to mwifiex_wait_queue_complete() to fix the problem.

Cc: <[email protected]> # 3.8
Reported-by: Daniel Drake <[email protected]>
Tested-by: Daniel Drake <[email protected]>
Tested-by: Marco Cesarano <[email protected]>
Signed-off-by: Amitkumar Karwar <[email protected]>
Signed-off-by: Bing Zhao <[email protected]>
---
drivers/net/wireless/mwifiex/cmdevt.c | 5 ++---
drivers/net/wireless/mwifiex/main.h | 4 ++--
drivers/net/wireless/mwifiex/scan.c | 8 ++++----
drivers/net/wireless/mwifiex/sta_ioctl.c | 10 ++--------
4 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/drivers/net/wireless/mwifiex/cmdevt.c b/drivers/net/wireless/mwifiex/cmdevt.c
index d19a88c..f47ad3a 100644
--- a/drivers/net/wireless/mwifiex/cmdevt.c
+++ b/drivers/net/wireless/mwifiex/cmdevt.c
@@ -484,8 +484,6 @@ int mwifiex_send_cmd_sync(struct mwifiex_private *priv, uint16_t cmd_no,

ret = mwifiex_send_cmd_async(priv, cmd_no, cmd_action, cmd_oid,
data_buf);
- if (!ret)
- ret = mwifiex_wait_queue_complete(adapter);

return ret;
}
@@ -588,9 +586,10 @@ int mwifiex_send_cmd_async(struct mwifiex_private *priv, uint16_t cmd_no,
if (cmd_no == HostCmd_CMD_802_11_SCAN) {
mwifiex_queue_scan_cmd(priv, cmd_node);
} else {
- adapter->cmd_queued = cmd_node;
mwifiex_insert_cmd_to_pending_q(adapter, cmd_node, true);
queue_work(adapter->workqueue, &adapter->main_work);
+ if (cmd_node->wait_q_enabled)
+ ret = mwifiex_wait_queue_complete(adapter, cmd_node);
}

return ret;
diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h
index 9206575..7255289 100644
--- a/drivers/net/wireless/mwifiex/main.h
+++ b/drivers/net/wireless/mwifiex/main.h
@@ -728,7 +728,6 @@ struct mwifiex_adapter {
u16 cmd_wait_q_required;
struct mwifiex_wait_queue cmd_wait_q;
u8 scan_wait_q_woken;
- struct cmd_ctrl_node *cmd_queued;
spinlock_t queue_lock; /* lock for tx queues */
struct completion fw_load;
u8 country_code[IEEE80211_COUNTRY_STRING_LEN];
@@ -1023,7 +1022,8 @@ int mwifiex_request_set_multicast_list(struct mwifiex_private *priv,
struct mwifiex_multicast_list *mcast_list);
int mwifiex_copy_mcast_addr(struct mwifiex_multicast_list *mlist,
struct net_device *dev);
-int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter);
+int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter,
+ struct cmd_ctrl_node *cmd_queued);
int mwifiex_bss_start(struct mwifiex_private *priv, struct cfg80211_bss *bss,
struct cfg80211_ssid *req_ssid);
int mwifiex_cancel_hs(struct mwifiex_private *priv, int cmd_type);
diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index bb60c27..d215b4d 100644
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -1388,10 +1388,13 @@ int mwifiex_scan_networks(struct mwifiex_private *priv,
list_del(&cmd_node->list);
spin_unlock_irqrestore(&adapter->scan_pending_q_lock,
flags);
- adapter->cmd_queued = cmd_node;
mwifiex_insert_cmd_to_pending_q(adapter, cmd_node,
true);
queue_work(adapter->workqueue, &adapter->main_work);
+
+ /* Perform internal scan synchronously */
+ if (!priv->scan_request)
+ mwifiex_wait_queue_complete(adapter, cmd_node);
} else {
spin_unlock_irqrestore(&adapter->scan_pending_q_lock,
flags);
@@ -1946,9 +1949,6 @@ int mwifiex_request_scan(struct mwifiex_private *priv,
/* Normal scan */
ret = mwifiex_scan_networks(priv, NULL);

- if (!ret)
- ret = mwifiex_wait_queue_complete(priv->adapter);
-
up(&priv->async_sem);

return ret;
diff --git a/drivers/net/wireless/mwifiex/sta_ioctl.c b/drivers/net/wireless/mwifiex/sta_ioctl.c
index 76d31de..8c943b6 100644
--- a/drivers/net/wireless/mwifiex/sta_ioctl.c
+++ b/drivers/net/wireless/mwifiex/sta_ioctl.c
@@ -54,16 +54,10 @@ int mwifiex_copy_mcast_addr(struct mwifiex_multicast_list *mlist,
* This function waits on a cmd wait queue. It also cancels the pending
* request after waking up, in case of errors.
*/
-int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter)
+int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter,
+ struct cmd_ctrl_node *cmd_queued)
{
int status;
- struct cmd_ctrl_node *cmd_queued;
-
- if (!adapter->cmd_queued)
- return 0;
-
- cmd_queued = adapter->cmd_queued;
- adapter->cmd_queued = NULL;

dev_dbg(adapter->dev, "cmd pending\n");
atomic_inc(&adapter->cmd_pending);
--
1.7.0.2


2013-03-16 01:47:38

by Bing Zhao

[permalink] [raw]
Subject: [PATCH 3.9 3/3] mwifiex: cancel cmd timer and free curr_cmd in shutdown process

curr_cmd points to the command that is in processing or waiting
for its command response from firmware. If the function shutdown
happens to occur at this time we should cancel the cmd timer and
put the command back to free queue.

Cc: <[email protected]> # 3.8
Tested-by: Marco Cesarano <[email protected]>
Signed-off-by: Bing Zhao <[email protected]>
---
drivers/net/wireless/mwifiex/init.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/net/wireless/mwifiex/init.c b/drivers/net/wireless/mwifiex/init.c
index cab3434..daf8801 100644
--- a/drivers/net/wireless/mwifiex/init.c
+++ b/drivers/net/wireless/mwifiex/init.c
@@ -709,6 +709,14 @@ mwifiex_shutdown_drv(struct mwifiex_adapter *adapter)
return ret;
}

+ /* cancel current command */
+ 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);
+ adapter->curr_cmd = NULL;
+ }
+
/* shut down mwifiex */
dev_dbg(adapter->dev, "info: shutdown mwifiex...\n");

--
1.7.0.2


2013-03-16 01:48:25

by Bing Zhao

[permalink] [raw]
Subject: [PATCH 3.9 2/3] mwifiex: skip pending commands after function shutdown

During rmmod mwifiex_sdio processing FUNC_SHUTDOWN command is
sent to firmware. Firmware expcets only FUNC_INIT once WLAN
function is shut down.

Any command pending in the command queue should be ignored and
freed.

Cc: <[email protected]> # 3.8
Tested-by: Daniel Drake <[email protected]>
Tested-by: Marco Cesarano <[email protected]>
Signed-off-by: Bing Zhao <[email protected]>
Signed-off-by: Amitkumar Karwar <[email protected]>
---
drivers/net/wireless/mwifiex/cmdevt.c | 17 ++++++++++++++---
1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mwifiex/cmdevt.c b/drivers/net/wireless/mwifiex/cmdevt.c
index f47ad3a..9a1302b 100644
--- a/drivers/net/wireless/mwifiex/cmdevt.c
+++ b/drivers/net/wireless/mwifiex/cmdevt.c
@@ -157,6 +157,20 @@ static int mwifiex_dnld_cmd_to_fw(struct mwifiex_private *priv,
return -1;
}

+ cmd_code = le16_to_cpu(host_cmd->command);
+ cmd_size = le16_to_cpu(host_cmd->size);
+
+ if (adapter->hw_status == MWIFIEX_HW_STATUS_RESET &&
+ cmd_code != HostCmd_CMD_FUNC_SHUTDOWN &&
+ cmd_code != HostCmd_CMD_FUNC_INIT) {
+ dev_err(adapter->dev,
+ "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);
+ return -1;
+ }
+
/* Set command sequence number */
adapter->seq_num++;
host_cmd->seq_num = cpu_to_le16(HostCmd_SET_SEQ_NO_BSS_INFO
@@ -168,9 +182,6 @@ static int mwifiex_dnld_cmd_to_fw(struct mwifiex_private *priv,
adapter->curr_cmd = cmd_node;
spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);

- cmd_code = le16_to_cpu(host_cmd->command);
- cmd_size = le16_to_cpu(host_cmd->size);
-
/* Adjust skb length */
if (cmd_node->cmd_skb->len > cmd_size)
/*
--
1.7.0.2