[PATCH 3/4] ath5k: implement multi-rate retry support, fix tx status reporting

[Felix Fietkau <nbd@openwrt.org>]

Clean up the tx status reporting, fix retry counters (short retries are
virtual collisions, not actual retries). Implement multi-rate retry
support.
This also fixes strong throughput fluctuations with rc80211_pid

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -530,6 +530,12 @@
 		goto err_irq;
 	}
 
+	/* set up multi-rate retry capabilities */
+	if (sc->ah->ah_version == AR5K_AR5212) {
+		hw->max_altrates = 3;
+		hw->max_altrate_tries = 11;
+	}
+
 	/* Finish private driver data initialization */
 	ret = ath5k_attach(pdev, hw);
 	if (ret)
@@ -1149,7 +1155,9 @@
 	struct sk_buff *skb = bf->skb;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	unsigned int pktlen, flags, keyidx = AR5K_TXKEYIX_INVALID;
-	int ret;
+	struct ieee80211_rate *rate;
+	unsigned int mrr_rate[3], mrr_tries[3];
+	int i, ret;
 
 	flags = AR5K_TXDESC_INTREQ | AR5K_TXDESC_CLRDMASK;
 
@@ -1174,6 +1182,22 @@
 	if (ret)
 		goto err_unmap;
 
+	memset(mrr_rate, 0, sizeof(mrr_rate));
+	memset(mrr_tries, 0, sizeof(mrr_tries));
+	for (i = 0; i < 3; i++) {
+		rate = ieee80211_get_alt_retry_rate(sc->hw, info, i);
+		if (!rate)
+			break;
+
+		mrr_rate[i] = rate->hw_value;
+		mrr_tries[i] = info->control.retries[i].limit;
+	}
+
+	ah->ah_setup_mrr_tx_desc(ah, ds,
+		mrr_rate[0], mrr_tries[0],
+		mrr_rate[1], mrr_tries[1],
+		mrr_rate[2], mrr_tries[2]);
+
 	ds->ds_link = 0;
 	ds->ds_data = bf->skbaddr;
 
@@ -1790,7 +1814,7 @@
 	struct ath5k_desc *ds;
 	struct sk_buff *skb;
 	struct ieee80211_tx_info *info;
-	int ret;
+	int i, ret;
 
 	spin_lock(&txq->lock);
 	list_for_each_entry_safe(bf, bf0, &txq->q, list) {
@@ -1812,7 +1836,25 @@
 		pci_unmap_single(sc->pdev, bf->skbaddr, skb->len,
 				PCI_DMA_TODEVICE);
 
-		info->status.retry_count = ts.ts_shortretry + ts.ts_longretry / 6;
+		memset(&info->status, 0, sizeof(info->status));
+		info->tx_rate_idx = ath5k_hw_to_driver_rix(sc,
+				ts.ts_rate[ts.ts_final_idx]);
+		info->status.retry_count = ts.ts_longretry;
+
+		for (i = 0; i < 4; i++) {
+			struct ieee80211_tx_altrate *r =
+				&info->status.retries[i];
+
+			if (ts.ts_rate[i]) {
+				r->rate_idx = ath5k_hw_to_driver_rix(sc, ts.ts_rate[i]);
+				r->limit = ts.ts_retry[i];
+			} else {
+				r->rate_idx = -1;
+				r->limit = 0;
+			}
+		}
+
+		info->status.excessive_retries = 0;
 		if (unlikely(ts.ts_status)) {
 			sc->ll_stats.dot11ACKFailureCount++;
 			if (ts.ts_status & AR5K_TXERR_XRETRY)
--- a/drivers/net/wireless/ath5k/desc.c
+++ b/drivers/net/wireless/ath5k/desc.c
@@ -318,6 +318,15 @@
 	return 0;
 }
 
+/* no mrr support for cards older than 5212 */
+static int
+ath5k_hw_setup_no_mrr(struct ath5k_hw *ah, struct ath5k_desc *desc,
+	unsigned int tx_rate1, u_int tx_tries1, u_int tx_rate2,
+	u_int tx_tries2, unsigned int tx_rate3, u_int tx_tries3)
+{
+	return 0;
+}
+
 /*
  * Proccess the tx status descriptor on 5210/5211
  */
@@ -352,8 +361,10 @@
 		AR5K_DESC_TX_STATUS1_ACK_SIG_STRENGTH);
 	ts->ts_antenna = 1;
 	ts->ts_status = 0;
-	ts->ts_rate = AR5K_REG_MS(tx_ctl->tx_control_0,
+	ts->ts_rate[0] = AR5K_REG_MS(tx_ctl->tx_control_0,
 		AR5K_2W_TX_DESC_CTL0_XMIT_RATE);
+	ts->ts_retry[0] = ts->ts_longretry;
+	ts->ts_final_idx = 0;
 
 	if (!(tx_status->tx_status_0 & AR5K_DESC_TX_STATUS0_FRAME_XMIT_OK)) {
 		if (tx_status->tx_status_0 &
@@ -405,29 +416,43 @@
 		AR5K_DESC_TX_STATUS1_XMIT_ANTENNA) ? 2 : 1;
 	ts->ts_status = 0;
 
-	switch (AR5K_REG_MS(tx_status->tx_status_1,
-			AR5K_DESC_TX_STATUS1_FINAL_TS_INDEX)) {
-	case 0:
-		ts->ts_rate = tx_ctl->tx_control_3 &
-			AR5K_4W_TX_DESC_CTL3_XMIT_RATE0;
-		break;
+	ts->ts_final_idx = AR5K_REG_MS(tx_status->tx_status_1,
+			AR5K_DESC_TX_STATUS1_FINAL_TS_INDEX);
+
+	/* The longretry counter has the number of un-acked retries
+	 * for the final rate. To get the total number of retries
+	 * we have to add the retry counters for the other rates
+	 * as well
+	 */
+	ts->ts_retry[ts->ts_final_idx] = ts->ts_longretry;
+	switch (ts->ts_final_idx) {
+	case 3:
+		ts->ts_rate[3] = AR5K_REG_MS(tx_ctl->tx_control_3,
+			AR5K_4W_TX_DESC_CTL3_XMIT_RATE3);
+
+		ts->ts_retry[2] = AR5K_REG_MS(tx_ctl->tx_control_2,
+			AR5K_4W_TX_DESC_CTL2_XMIT_TRIES2);
+		ts->ts_longretry += ts->ts_retry[2];
+		/* fall through */
+	case 2:
+		ts->ts_rate[2] = AR5K_REG_MS(tx_ctl->tx_control_3,
+			AR5K_4W_TX_DESC_CTL3_XMIT_RATE2);
+
+		ts->ts_retry[1] = AR5K_REG_MS(tx_ctl->tx_control_2,
+			AR5K_4W_TX_DESC_CTL2_XMIT_TRIES1);
+		ts->ts_longretry += ts->ts_retry[1];
+		/* fall through */
 	case 1:
-		ts->ts_rate = AR5K_REG_MS(tx_ctl->tx_control_3,
+		ts->ts_rate[1] = AR5K_REG_MS(tx_ctl->tx_control_3,
 			AR5K_4W_TX_DESC_CTL3_XMIT_RATE1);
-		ts->ts_longretry += AR5K_REG_MS(tx_ctl->tx_control_2,
+
+		ts->ts_retry[0] = AR5K_REG_MS(tx_ctl->tx_control_2,
 			AR5K_4W_TX_DESC_CTL2_XMIT_TRIES1);
-		break;
-	case 2:
-		ts->ts_rate = AR5K_REG_MS(tx_ctl->tx_control_3,
-			AR5K_4W_TX_DESC_CTL3_XMIT_RATE2);
-		ts->ts_longretry += AR5K_REG_MS(tx_ctl->tx_control_2,
-			AR5K_4W_TX_DESC_CTL2_XMIT_TRIES2);
-		break;
-	case 3:
-		ts->ts_rate = AR5K_REG_MS(tx_ctl->tx_control_3,
-			AR5K_4W_TX_DESC_CTL3_XMIT_RATE3);
-		ts->ts_longretry += AR5K_REG_MS(tx_ctl->tx_control_2,
-			AR5K_4W_TX_DESC_CTL2_XMIT_TRIES3);
+		ts->ts_longretry += ts->ts_retry[0];
+		/* fall through */
+	case 0:
+		ts->ts_rate[0] = tx_ctl->tx_control_3 &
+			AR5K_4W_TX_DESC_CTL3_XMIT_RATE0;
 		break;
 	}
 
@@ -653,7 +678,7 @@
 	} else {
 		ah->ah_setup_rx_desc = ath5k_hw_setup_rx_desc;
 		ah->ah_setup_tx_desc = ath5k_hw_setup_2word_tx_desc;
-		ah->ah_setup_mrr_tx_desc = ath5k_hw_setup_mrr_tx_desc;
+		ah->ah_setup_mrr_tx_desc = ath5k_hw_setup_no_mrr;
 		ah->ah_proc_tx_desc = ath5k_hw_proc_2word_tx_status;
 	}
 
--- a/drivers/net/wireless/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath5k/ath5k.h
@@ -418,7 +418,9 @@
 	u16	ts_seqnum;
 	u16	ts_tstamp;
 	u8	ts_status;
-	u8	ts_rate;
+	u8	ts_rate[4];
+	u8	ts_retry[4];
+	u8	ts_final_idx;
 	s8	ts_rssi;
 	u8	ts_shortretry;
 	u8	ts_longretry;