wimax/i2400m: fix the race condition for accessing TX queue

The race condition happens when the TX queue is accessed by
the TX work while the same TX queue is being destroyed because
a bus reset is triggered either by debugfs entry or simply
by failing waking up the device from WiMAX IDLE mode.

This fix is to prevent the TX queue from being accessed by
multiple threads

Signed-off-by: Cindy H Kao <cindy.h.kao@intel.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/net/wimax/i2400m/i2400m-sdio.h b/drivers/net/wimax/i2400m/i2400m-sdio.h
index b9c4bed3b457..360d4fb195f4 100644
--- a/drivers/net/wimax/i2400m/i2400m-sdio.h
+++ b/drivers/net/wimax/i2400m/i2400m-sdio.h
@@ -99,7 +99,10 @@ enum {
  *
  * @tx_workqueue: workqeueue used for data TX; we don't use the
  *     system's workqueue as that might cause deadlocks with code in
- *     the bus-generic driver.
+ *     the bus-generic driver. The read/write operation to the queue
+ *     is protected with spinlock (tx_lock in struct i2400m) to avoid
+ *     the queue being destroyed in the middle of a the queue read/write
+ *     operation.
  *
  * @debugfs_dentry: dentry for the SDIO specific debugfs files
  *