rt2x00 : hw support tdone implementation.

index 7899789..3ac1df0 100644
@@ -920,100 +920,96 @@ static void rt2800pci_txdone(struct rt2x00_dev *rt2x00dev)
 {
 	struct data_queue *queue;
 	struct queue_entry *entry;
-	struct queue_entry *entry_done;
-	struct queue_entry_priv_pci *entry_priv;
+	__le32 *txwi;
 	struct txdone_entry_desc txdesc;
 	u32 word;
 	u32 reg;
-	u32 old_reg;
-	unsigned int type;
-	unsigned int index;
-	u16 mcs, real_mcs;
-
+	int i;
+	int wcid, ack, pid, tx_wcid, tx_ack, tx_pid;
+	u16 mcs, tx_mcs;
+	
 	/*
-	 * During each loop we will compare the freshly read
-	 * TX_STA_FIFO register value with the value read from
-	 * the previous loop. If the 2 values are equal then
-	 * we should stop processing because the chance it
-	 * quite big that the device has been unplugged and
-	 * we risk going into an endless loop.
+	 * To avoid an endlees loop, we only read the TX_STA_FIFO register up
+	 * to 256 times (this is enought to get all values from the FIFO). In
+	 * normal situation, the loop is terminated when we reach a value with
+	 * TX_STA_FIFO_VALID bit is 0.
 	 */
-	old_reg = 0;
-
-	while (1) {
+	
+	for (i=0; i<256; i++) {
 		rt2800_register_read(rt2x00dev, TX_STA_FIFO, &reg);
 		if (!rt2x00_get_field32(reg, TX_STA_FIFO_VALID))
 			break;
 
-		if (old_reg == reg)
-			break;
-		old_reg = reg;
+		wcid    = rt2x00_get_field32(reg, TX_STA_FIFO_WCID);
+		ack     = rt2x00_get_field32(reg, TX_STA_FIFO_TX_ACK_REQUIRED);
+		pid     = rt2x00_get_field32(reg, TX_STA_FIFO_PID_TYPE);
 
 		/*
 		 * Skip this entry when it contains an invalid
 		 * queue identication number.
 		 */
-		type = rt2x00_get_field32(reg, TX_STA_FIFO_PID_TYPE) - 1;
-		if (type >= QID_RX)
+		if (pid < 1)
 			continue;
 
-		queue = rt2x00queue_get_queue(rt2x00dev, type);
+		queue = rt2x00queue_get_queue(rt2x00dev, pid - 1);
 		if (unlikely(!queue))
 			continue;
 
 		/*
-		 * Skip this entry when it contains an invalid
-		 * index number.
+		 * Inside each queue, we process each entry in a chronological
+		 * order. We first check that the queue is not empty.
 		 */
-		index = rt2x00_get_field32(reg, TX_STA_FIFO_WCID) - 1;
-		if (unlikely(index >= queue->limit))
+		if (queue->length == 0)
 			continue;
+		entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
 
-		entry = &queue->entries[index];
-		entry_priv = entry->priv_data;
-		rt2x00_desc_read((__le32 *)entry->skb->data, 0, &word);
+		/* Check if we got a match by looking at WCID/ACK/PID
+		 * fields */
+		txwi = (__le32 *)(entry->skb->data -
+				  rt2x00dev->hw->extra_tx_headroom);
 
-		entry_done = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
-		while (entry != entry_done) {
-			/*
-			 * Catch up.
-			 * Just report any entries we missed as failed.
-			 */
-			WARNING(rt2x00dev,
-				"TX status report missed for entry %d\n",
-				entry_done->entry_idx);
-
-			txdesc.flags = 0;
-			__set_bit(TXDONE_UNKNOWN, &txdesc.flags);
-			txdesc.retry = 0;
+		rt2x00_desc_read(txwi, 1, &word);
+		tx_wcid = rt2x00_get_field32(word, TXWI_W1_WIRELESS_CLI_ID);
+		tx_ack  = rt2x00_get_field32(word, TXWI_W1_ACK);
+		tx_pid  = rt2x00_get_field32(word, TXWI_W1_PACKETID);
 
-			rt2x00lib_txdone(entry_done, &txdesc);
-			entry_done = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
-		}
+		if ((wcid != tx_wcid) || (ack != tx_ack) || (pid != tx_pid))
+			WARNING(rt2x00dev, "invalid TX_STA_FIFO content\n");
 
 		/*
 		 * Obtain the status about this packet.
 		 */
-		txdesc.flags = 0;
-		if (rt2x00_get_field32(reg, TX_STA_FIFO_TX_SUCCESS))
-			__set_bit(TXDONE_SUCCESS, &txdesc.flags);
-		else
-			__set_bit(TXDONE_FAILURE, &txdesc.flags);
+		mcs = rt2x00_get_field32(reg, TX_STA_FIFO_MCS);
+		rt2x00_desc_read(txwi, 0, &word);
+		tx_mcs = rt2x00_get_field32(word, TXWI_W0_MCS);
 
 		/*
 		 * Ralink has a retry mechanism using a global fallback
-		 * table. We setup this fallback table to try immediate
-		 * lower rate for all rates. In the TX_STA_FIFO,
-		 * the MCS field contains the MCS used for the successfull
-		 * transmission. If the first transmission succeed,
-		 * we have mcs == tx_mcs. On the second transmission,
-		 * we have mcs = tx_mcs - 1. So the number of
-		 * retry is (tx_mcs - mcs).
+		 * table. We setup this fallback table to try the immediate
+		 * lower rate for all rates. In the TX_STA_FIFO, the MCS field
+		 * always contains the MCS used for the last transmission, be
+		 * it successful or not.
 		 */
-		mcs = rt2x00_get_field32(word, TXWI_W0_MCS);
-		real_mcs = rt2x00_get_field32(reg, TX_STA_FIFO_MCS);
+
+		txdesc.flags = 0;
+		if (rt2x00_get_field32(reg, TX_STA_FIFO_TX_SUCCESS)) {
+			/*
+			 * Transmission succeeded. The number of retries is
+			 * tx_mcs - mcs
+			 */
+			__set_bit(TXDONE_SUCCESS, &txdesc.flags);
+			txdesc.retry = ((tx_mcs > mcs) ? tx_mcs - mcs : 0);
+		} else {
+			/*
+			 * Transmission failed. The number of retries is
+			 * always 7 in this case (for a total number of 8
+			 * frames sent).
+			 */
+			__set_bit(TXDONE_FAILURE, &txdesc.flags);
+			txdesc.retry = 7;
+		}
+
 		__set_bit(TXDONE_FALLBACK, &txdesc.flags);
-		txdesc.retry = mcs - min(mcs, real_mcs);
 
 		rt2x00lib_txdone(entry, &txdesc);
 	}

64 lines not on this page · raw message

index c1e482b..4e801c3 100644
@@ -214,7 +214,7 @@ struct rxdone_entry_desc {
  *
  * @TXDONE_UNKNOWN: Hardware could not determine success of transmission.
  * @TXDONE_SUCCESS: Frame was successfully send
- * @TXDONE_FALLBACK: Frame was successfully send using a fallback rate.
+ * @TXDONE_FALLBACK: Frame was sent using a fallback rate table.
  * @TXDONE_FAILURE: Frame was not successfully send
  * @TXDONE_EXCESSIVE_RETRY: In addition to &TXDONE_FAILURE, the
  *	frame transmission failed due to excessive retries.

@@ -234,7 +234,9 @@ enum txdone_entry_desc_flags {
  * after the device is done with transmission.
  *
  * @flags: TX done flags (See &enum txdone_entry_desc_flags).
- * @retry: Retry count.
+ * @retry: Retry count. If TXDONE_FALLBACK is not set, the frame was sent
+ * (retry+1) times at the same rate. If TXDONE_FALLBACK is set, the frame was
+ * sent once for each lower rates, up to (retry+1) times in total.
  */
 struct txdone_entry_desc {
 	unsigned long flags;