rt2800usb: read TX_STA_FIFO asynchronously
Trying to fix the "TX status report missed" warnings
by reading the TX_STA_FIFO entries as quickly as possible.
The TX_STA_FIFO is too small in hardware, thus reading
it only from the workqueue is too slow and entries get lost.
Start an asynchronous read of the TX_STA_FIFO directly from
the TX URB completion callback (atomic context, thus it cannot
use the blocking rt2800_register_read()). If the async
read returns a valid FIFO entry, it is pushed into a larger
FIFO inside struct rt2x00_dev, until rt2800_txdone() picks
it up.
A .tx_dma_done callback is added to struct rt2x00lib_ops
to trigger the async read from the URB completion callback.
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>
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index f3ce5e8..862430e 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -98,6 +98,35 @@
}
}
+static void rt2800usb_tx_sta_fifo_read_completed(struct rt2x00_dev *rt2x00dev,
+ int urb_status, u32 tx_status)
+{
+ if (urb_status) {
+ WARNING(rt2x00dev, "rt2x00usb_register_read_async failed: %d\n", urb_status);
+ return;
+ }
+
+ /* try to read all TX_STA_FIFO entries before scheduling txdone_work */
+ if (rt2x00_get_field32(tx_status, TX_STA_FIFO_VALID)) {
+ if (!kfifo_put(&rt2x00dev->txstatus_fifo, &tx_status)) {
+ WARNING(rt2x00dev, "TX status FIFO overrun, "
+ "drop tx status report.\n");
+ queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+ } else
+ rt2x00usb_register_read_async(rt2x00dev, TX_STA_FIFO,
+ rt2800usb_tx_sta_fifo_read_completed);
+ } else if (!kfifo_is_empty(&rt2x00dev->txstatus_fifo))
+ queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+}
+
+static void rt2800usb_tx_dma_done(struct queue_entry *entry)
+{
+ struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
+
+ rt2x00usb_register_read_async(rt2x00dev, TX_STA_FIFO,
+ rt2800usb_tx_sta_fifo_read_completed);
+}
+
/*
* Firmware functions
*/
@@ -565,6 +594,7 @@
__set_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags);
__set_bit(CAPABILITY_LINK_TUNING, &rt2x00dev->cap_flags);
__set_bit(REQUIRE_HT_TX_DESC, &rt2x00dev->cap_flags);
+ __set_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags);
/*
* Set the rssi offset.
@@ -635,6 +665,7 @@
.kick_queue = rt2x00usb_kick_queue,
.stop_queue = rt2800usb_stop_queue,
.flush_queue = rt2x00usb_flush_queue,
+ .tx_dma_done = rt2800usb_tx_dma_done,
.write_tx_desc = rt2800usb_write_tx_desc,
.write_tx_data = rt2800usb_write_tx_data,
.write_beacon = rt2800_write_beacon,