rt2x00: Implement watchdog monitoring

Implement watchdog monitoring for USB devices (PCI support can
be added later). This will determine if URBs being uploaded to
the hardware are actually returning. Both rt2500usb and rt2800usb
have shown that URBs being uploaded can remain hanging without
being released by the hardware.
By using this watchdog, a queue can be reset when this occurs.
For rt2800usb it has been tested that the connection is preserved
even though this interruption.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.h b/drivers/net/wireless/rt2x00/rt2x00queue.h
index bd54f55a8cb..191e7775a9c 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.h
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.h
@@ -446,6 +446,8 @@ struct data_queue {
 	enum data_queue_qid qid;
 
 	spinlock_t lock;
+	unsigned long last_index;
+	unsigned long last_index_done;
 	unsigned int count;
 	unsigned short limit;
 	unsigned short threshold;
@@ -599,6 +601,15 @@ static inline int rt2x00queue_threshold(struct data_queue *queue)
 }
 
 /**
+ * rt2x00queue_timeout - Check if a timeout occured for this queue
+ * @queue: Queue to check.
+ */
+static inline int rt2x00queue_timeout(struct data_queue *queue)
+{
+	return time_after(queue->last_index, queue->last_index_done + (HZ / 10));
+}
+
+/**
  * _rt2x00_desc_read - Read a word from the hardware descriptor.
  * @desc: Base descriptor address
  * @word: Word index from where the descriptor should be read.