mwifiex: fix race when queuing commands
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: <stable@vger.kernel.org> # 3.8
Reported-by: Daniel Drake <dsd@laptop.org>
Tested-by: Daniel Drake <dsd@laptop.org>
Tested-by: Marco Cesarano <marco@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/cmdevt.c b/drivers/net/wireless/mwifiex/cmdevt.c
index 20a6c55..2ffabdd 100644
--- a/drivers/net/wireless/mwifiex/cmdevt.c
+++ b/drivers/net/wireless/mwifiex/cmdevt.c
@@ -484,8 +484,6 @@
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 @@
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;