rt2800usb: add timer to handle TX_STA_FIFO

TX status is reported by the hardware when a packet has been
sent (or after TX failed after possible retries), which is some
time after the DMA completion.  Since the rt2800usb hardware can
not signal interrupts we have to use a timer, otherwise the
TX status would only be read by the next packet's TX DMA
completion, or by the watchdog thread.

Signed-off-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 14736e217947..34b8a887831b 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -280,7 +280,9 @@ static void rt2x00usb_interrupt_txdone(struct urb *urb)
          * Schedule the delayed work for reading the TX status
          * from the device.
          */
-        queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+        if (!test_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags) ||
+            !kfifo_is_empty(&rt2x00dev->txstatus_fifo))
+                queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
 }
 
 static bool rt2x00usb_kick_tx_entry(struct queue_entry *entry, void* data)
@@ -816,6 +818,7 @@ int rt2x00usb_probe(struct usb_interface *usb_intf,
 
         INIT_WORK(&rt2x00dev->rxdone_work, rt2x00usb_work_rxdone);
         INIT_WORK(&rt2x00dev->txdone_work, rt2x00usb_work_txdone);
+        init_timer(&rt2x00dev->txstatus_timer);
 
         retval = rt2x00usb_alloc_reg(rt2x00dev);
         if (retval)