ath9k: cleanup try count for MRR in rate control

This has no functional change and just cleans up the code
to be more legible and removes a useless variable for
Multi Rate Retry.

For regular frames we use 2 retries for MRR segments [0-2].
For the last MRR segment [3] we use 4.

MRR[0] = 2
MRR[1] = 2
MRR[2] = 2
MRR[3] = 4

Cc: Derek Smithies <derek@indranet.co.nz>
Cc: Chittajit Mitra <Chittajit.Mitra@Atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 20 insertions, 9 deletions

diff --git a/drivers/net/wireless/ath/ath9k/rc.c b/drivers/net/wireless/ath/ath9k/rc.c
index d7f403080f7a..a23b66bdbe92 100644
--- a/drivers/net/wireless/ath/ath9k/rc.c
+++ b/drivers/net/wireless/ath/ath9k/rc.c
@@ -853,9 +853,21 @@ static void ath_rc_ratefind(struct ath_softc *sc,
         struct ieee80211_tx_rate *rates = tx_info->control.rates;
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
         __le16 fc = hdr->frame_control;
-        u8 try_per_rate = 0, i = 0, rix, nrix;
+        u8 try_per_rate, i = 0, rix, nrix;
         int is_probe = 0;
 
+        /*
+         * For Multi Rate Retry we use a different number of
+         * retry attempt counts. This ends up looking like this:
+         *
+         * MRR[0] = 2
+         * MRR[1] = 2
+         * MRR[2] = 2
+         * MRR[3] = 4
+         *
+         */
+        try_per_rate = sc->hw->max_rate_tries;
+
         rate_table = sc->cur_rate_table;
         rix = ath_rc_ratefind_ht(sc, ath_rc_priv, rate_table, &is_probe);
         nrix = rix;
@@ -866,7 +878,6 @@ static void ath_rc_ratefind(struct ath_softc *sc,
                 ath_rc_rate_set_series(rate_table, &rates[i++], txrc,
                                        1, nrix, 0);
 
-                try_per_rate = (ATH_11N_TXMAXTRY/4);
                 /* Get the next tried/allowed rate. No RTS for the next series
                  * after the probe rate
                  */
@@ -877,7 +888,6 @@ static void ath_rc_ratefind(struct ath_softc *sc,
 
                 tx_info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
         } else {
-                try_per_rate = (ATH_11N_TXMAXTRY/4);
                 /* Set the choosen rate. No RTS for first series entry. */
                 ath_rc_rate_set_series(rate_table, &rates[i++], txrc,
                                        try_per_rate, nrix, 0);
@@ -885,18 +895,19 @@ static void ath_rc_ratefind(struct ath_softc *sc,
 
         /* Fill in the other rates for multirate retry */
         for ( ; i < 4; i++) {
-                u8 try_num;
                 u8 min_rate;
 
-                try_num = ((i + 1) == 4) ?
-                        ATH_11N_TXMAXTRY - (try_per_rate * i) : try_per_rate ;
+                /* Use twice the number of tries for the last MRR segment. */
+                if (i + 1 == 4)
+                        try_per_rate = 4;
+
                 min_rate = (((i + 1) == 4) && 0);
 
                 nrix = ath_rc_rate_getidx(sc, ath_rc_priv,
                                           rate_table, nrix, 1, min_rate);
                 /* All other rates in the series have RTS enabled */
                 ath_rc_rate_set_series(rate_table, &rates[i], txrc,
-                                       try_num, nrix, 1);
+                                       try_per_rate, nrix, 1);
         }
 
         /*
@@ -1529,7 +1540,7 @@ static void ath_tx_status(void *priv, struct ieee80211_supported_band *sband,
         /*
          * If underrun error is seen assume it as an excessive retry only
          * if prefetch trigger level have reached the max (0x3f for 5416)
-         * Adjust the long retry as if the frame was tried ATH_11N_TXMAXTRY
+         * Adjust the long retry as if the frame was tried hw->max_rate_tries
          * times. This affects how ratectrl updates PER for the failed rate.
          */
         if (tx_info_priv->tx.ts_flags &
@@ -1544,7 +1555,7 @@ static void ath_tx_status(void *priv, struct ieee80211_supported_band *sband,
                 tx_status = 1;
 
         ath_rc_tx_status(sc, ath_rc_priv, tx_info, final_ts_idx, tx_status,
-                         (is_underrun) ? ATH_11N_TXMAXTRY :
+                         (is_underrun) ? sc->hw->max_rate_tries :
                          tx_info_priv->tx.ts_longretry);
 
         /* Check if aggregation has to be enabled for this tid */