ath9k: Add tx-failed counter.

This counts any failure during getting packets into
the DMA buffers, including out-of-memory, etc.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/debug.c

@@ -529,6 +529,7 @@ static ssize_t read_file_xmit(struct file *file, char __user *user_buf,
 	PR("hw-put-tx-buf:   ", puttxbuf);
 	PR("hw-tx-start:     ", txstart);
 	PR("hw-tx-proc-desc: ", txprocdesc);
+	PR("TX-Failed:       ", txfailed);
 	len += snprintf(buf + len, size - len,
 			"%s%11p%11p%10p%10p\n", "txq-memory-address:",
 			sc->tx.txq_map[WME_AC_BE],

drivers/net/wireless/ath/ath9k/debug.h

@@ -113,6 +113,7 @@ struct ath_interrupt_stats {
  * @puttxbuf: Number of times hardware was given txbuf to write.
  * @txstart:  Number of times hardware was told to start tx.
  * @txprocdesc:  Number of times tx descriptor was processed
+ * @txfailed:  Out-of-memory or other errors in xmit path.
  */
 struct ath_tx_stats {
 	u32 tx_pkts_all;
@@ -135,6 +136,7 @@ struct ath_tx_stats {
 	u32 puttxbuf;
 	u32 txstart;
 	u32 txprocdesc;
+	u32 txfailed;
 };
 
 /**

drivers/net/wireless/ath/ath9k/main.c

@@ -1152,6 +1152,7 @@ static void ath9k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 
 	if (ath_tx_start(hw, skb, &txctl) != 0) {
 		ath_dbg(common, XMIT, "TX failed\n");
+		TX_STAT_INC(txctl.txq->axq_qnum, txfailed);
 		goto exit;
 	}