2012-08-07 01:15:47

by Sujith Manoharan

[permalink] [raw]
Subject: [RFC 10/14] ath9k: Fix RTS/CTS rate selection

The current method of assigning the RTS/CTS rate is completely
broken for HT mode and breaks P2P operation. Fix this by using
the basic_rates provided to the driver by mac80211. For now,
choose the lowest supported basic rate for HT frames.

Signed-off-by: Sujith Manoharan <[email protected]>
---
drivers/net/wireless/ath/ath9k/rc.c | 41 +++++++++++++------------------------
1 file changed, 14 insertions(+), 27 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/rc.c b/drivers/net/wireless/ath/ath9k/rc.c
index 78192c1..a94c52b 100644
--- a/drivers/net/wireless/ath/ath9k/rc.c
+++ b/drivers/net/wireless/ath/ath9k/rc.c
@@ -699,37 +699,25 @@ static void ath_rc_rate_set_rtscts(struct ath_softc *sc,
const struct ath_rate_table *rate_table,
struct ieee80211_tx_info *tx_info)
{
- struct ieee80211_tx_rate *rates = tx_info->control.rates;
- int i = 0, rix = 0, cix, enable_g_protection = 0;
+ struct ieee80211_bss_conf *bss_conf;

- /* get the cix for the lowest valid rix */
- for (i = 3; i >= 0; i--) {
- if (rates[i].count && (rates[i].idx >= 0)) {
- rix = ath_rc_get_rateindex(rate_table, &rates[i]);
- break;
- }
- }
- cix = rate_table->info[rix].ctrl_rate;
+ if (!tx_info->control.vif)
+ return;
+ /*
+ * For legacy frames, mac80211 takes care of CTS protection.
+ */
+ if (!(tx_info->control.rates[0].flags & IEEE80211_TX_RC_MCS))
+ return;
+
+ bss_conf = &tx_info->control.vif->bss_conf;

- /* All protection frames are transmited at 2Mb/s for 802.11g,
- * otherwise we transmit them at 1Mb/s */
- if (sc->hw->conf.channel->band == IEEE80211_BAND_2GHZ &&
- !conf_is_ht(&sc->hw->conf))
- enable_g_protection = 1;
+ if (!bss_conf->basic_rates)
+ return;

/*
- * If 802.11g protection is enabled, determine whether to use RTS/CTS or
- * just CTS. Note that this is only done for OFDM/HT unicast frames.
+ * For now, use the lowest allowed basic rate for HT frames.
*/
- if ((tx_info->control.vif &&
- tx_info->control.vif->bss_conf.use_cts_prot) &&
- (rate_table->info[rix].phy == WLAN_RC_PHY_OFDM ||
- WLAN_RC_PHY_HT(rate_table->info[rix].phy))) {
- rates[0].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
- cix = rate_table->info[enable_g_protection].ctrl_rate;
- }
-
- tx_info->control.rts_cts_rate_idx = cix;
+ tx_info->control.rts_cts_rate_idx = __ffs(bss_conf->basic_rates);
}

static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
@@ -853,7 +841,6 @@ static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
rates[0].count = ATH_TXMAXTRY;
}

- /* Setup RTS/CTS */
ath_rc_rate_set_rtscts(sc, rate_table, tx_info);
}

--
1.7.11.4