rt2x00: Split watchdog check into a DMA and STATUS timeout

The watchdog for rt2800usb triggers frequently causing all URB's
to be canceled often enough to interrupt the normal TX flow.
More research indicated that not the URB upload to the USB host
were hanging, but instead the TX status reports.

To correctly detect what is going on, we introduce Q_INDEX_DMA_DONE
which is an index counter between Q_INDEX_DONE and Q_INDEX and indicates
if the frame has been transfered to the device.

This also requires the rt2x00queue timeout functions to be updated
to differentiate between a DMA timeout (time between Q_INDEX and
Q_INDEX_DMA_DONE timeout) and a STATUS timeout (time between
Q_INDEX_DMA_DONE and Q_INDEX_DONE timeout)

All Q_INDEX_DMA_DONE code was taken from the RFC from
Helmut Schaa <helmut.schaa@googlemail.com> for the implementation
for watchdog for rt2800pci.

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

1 files changed, 8 insertions, 5 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index ecf57635ae5..6d41599a090 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -731,13 +731,13 @@ void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
 	if (queue->index[index] >= queue->limit)
 		queue->index[index] = 0;
 
+	queue->last_action[index] = jiffies;
+
 	if (index == Q_INDEX) {
 		queue->length++;
-		queue->last_index = jiffies;
 	} else if (index == Q_INDEX_DONE) {
 		queue->length--;
 		queue->count++;
-		queue->last_index_done = jiffies;
 	}
 
 	spin_unlock_irqrestore(&queue->lock, irqflags);
@@ -746,14 +746,17 @@ void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
 static void rt2x00queue_reset(struct data_queue *queue)
 {
 	unsigned long irqflags;
+	unsigned int i;
 
 	spin_lock_irqsave(&queue->lock, irqflags);
 
 	queue->count = 0;
 	queue->length = 0;
-	queue->last_index = jiffies;
-	queue->last_index_done = jiffies;
-	memset(queue->index, 0, sizeof(queue->index));
+
+	for (i = 0; i < Q_INDEX_MAX; i++) {
+		queue->index[i] = 0;
+		queue->last_action[i] = jiffies;
+	}
 
 	spin_unlock_irqrestore(&queue->lock, irqflags);
 }