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/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index 0e2c006..d79c8fd 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -730,34 +730,20 @@
struct data_queue *queue;
struct queue_entry *entry;
u32 reg;
- u8 pid;
- int i;
+ u8 qid;
- /*
- * TX_STA_FIFO is a stack of X entries, hence read TX_STA_FIFO
- * at most X times and also stop processing once the TX_STA_FIFO_VALID
- * flag is not set anymore.
- *
- * The legacy drivers use X=TX_RING_SIZE but state in a comment
- * that the TX_STA_FIFO stack has a size of 16. We stick to our
- * tx ring size for now.
- */
- for (i = 0; i < rt2x00dev->ops->tx->entry_num; i++) {
- rt2800_register_read(rt2x00dev, TX_STA_FIFO, ®);
- if (!rt2x00_get_field32(reg, TX_STA_FIFO_VALID))
- break;
+ while (kfifo_get(&rt2x00dev->txstatus_fifo, ®)) {
- /*
- * Skip this entry when it contains an invalid
- * queue identication number.
+ /* TX_STA_FIFO_PID_QUEUE is a 2-bit field, thus
+ * qid is guaranteed to be one of the TX QIDs
*/
- pid = rt2x00_get_field32(reg, TX_STA_FIFO_PID_QUEUE);
- if (pid >= QID_RX)
+ qid = rt2x00_get_field32(reg, TX_STA_FIFO_PID_QUEUE);
+ queue = rt2x00queue_get_tx_queue(rt2x00dev, qid);
+ if (unlikely(!queue)) {
+ WARNING(rt2x00dev, "Got TX status for an unavailable "
+ "queue %u, dropping\n", qid);
continue;
-
- queue = rt2x00queue_get_tx_queue(rt2x00dev, pid);
- if (unlikely(!queue))
- continue;
+ }
/*
* Inside each queue, we process each entry in a chronological