[PATCH 04/21] ath9k: cleanup try count for MRR in rate control

Luis R. Rodriguez
2009-07-15T00:14:29Z

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>
---
drivers/net/wireless/ath/ath9k/ath9k.h | 1 -
drivers/net/wireless/ath/ath9k/main.c | 3 ++-
drivers/net/wireless/ath/ath9k/rc.c | 29 ++++++++++++++++++++---------
3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index eb9d522..3afd7ee 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -164,7 +164,6 @@ void ath_descdma_cleanup(struct ath_softc *sc, struct ath_descdma *dd,
#define WME_NUM_TID 16
#define ATH_TXBUF 512
#define ATH_TXMAXTRY 13
-#define ATH_11N_TXMAXTRY 10
#define ATH_MGT_TXMAXTRY 4
#define WME_BA_BMP_SIZE 64
#define WME_MAX_BA WME_BA_BMP_SIZE
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 961b0ce..19df788 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1540,7 +1540,8 @@ void ath_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
hw->max_rates = 4;
hw->channel_change_time = 5000;
hw->max_listen_interval = 10;
- hw->max_rate_tries = ATH_11N_TXMAXTRY;
+ /* Hardware supports 10 but we use 4 */
+ hw->max_rate_tries = 4;
hw->sta_data_size = sizeof(struct ath_node);
hw->vif_data_size = sizeof(struct ath_vif);

diff --git a/drivers/net/wireless/ath/ath9k/rc.c b/drivers/net/wireless/ath/ath9k/rc.c
index d7f4030..a23b66b 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 */
--
1.6.0.6