Skip to contentSkip to conversation

mac80211: force use_short_slot=true for 5GHz

PATCH Superseded Felix Fietkau 1 participant 4 messages Jan 15, 2010

Subsystems (2)
mac80211 Qualcomm Atheros ATH9K wireless driver
lore
Share & tools
lore

Felix Fietkau

author
#0 lore raw

PATCH 1/3 mac80211: force use_short_slot=true for 5GHz

Normally 5GHz does not have a concept of long vs short slot time, however the slot time that it ends up using is the same as for 2.4 GHZ and use_short_slot == true
Because of that, it makes more sense to force use_short_slot = true whenever 5 GHz is being used, so that this particular check does not have to be in every single driver that uses this flag.

Signed-off-by Felix Fietkau <[email protected]>

---

net/mac80211/mlme.c +2 -0
@@ -670,6 +670,8 @@ static u32 ieee80211_handle_bss_capabili
 	}
 
 	use_short_slot = !!(capab & WLAN_CAPABILITY_SHORT_SLOT_TIME);
+	if (sdata->local->hw.conf.channel->band == IEEE80211_BAND_5GHZ)
+		use_short_slot = true;
 
 	if (use_protection != bss_conf->use_cts_prot) {
 		bss_conf->use_cts_prot = use_protection;
author
#1 lore raw

PATCH 2/3 ath9k: cleanup slot time and ack/cts timeout handling

Previously ath9k left the initialization of slot timing and ACK/CTS timeout to the mode specific initvals. This does not handle short vs long slot in 2.4 GHz and uses a rather strange value for the 2.4 GHz ACK timeout (64 usec).
This patch uses the proper ath9k_hw functions for setting slot time and timeouts and also implements the switch between short and long slot time in 2.4 GHz

Signed-off-by Felix Fietkau <[email protected]>

---

drivers/net/wireless/ath/ath9k/main.c +20 -0
@@ -1790,6 +1790,7 @@ static void ath9k_bss_info_changed(struc
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ath_vif *avp = (void *)vif->drv_priv;
+	int slottime;
 	int error;
 
 	mutex_lock(&sc->mutex);

@@ -1825,6 +1826,25 @@ static void ath9k_bss_info_changed(struc
 			ath_beacon_config(sc, vif);
 	}
 
+	if (changed & BSS_CHANGED_ERP_SLOT) {
+		if (bss_conf->use_short_slot)
+			slottime = 9;
+		else
+			slottime = 20;
+		if (vif->type == NL80211_IFTYPE_AP) {
+			/*
+			 * Defer update, so that connected stations can adjust
+			 * their settings at the same time.
+			 * See beacon.c for more details
+			 */
+			sc->beacon.slottime = slottime;
+			sc->beacon.updateslot = UPDATE;
+		} else {
+			ah->slottime = slottime;
+			ath9k_hw_init_global_settings(ah);
+		}
+	}
+
 	/* Disable transmission of beacons */
 	if ((changed & BSS_CHANGED_BEACON_ENABLED) && !bss_conf->enable_beacon)
 		ath9k_hw_stoptxdma(sc->sc_ah, sc->beacon.beaconq);
drivers/net/wireless/ath/ath9k/hw.c +32 -71

153 lines not on this page · raw message

drivers/net/wireless/ath/ath9k/hw.h +1 -3
@@ -553,8 +553,6 @@ struct ath_hw {
 	int16_t txpower_indexoffset;
 	u32 beacon_interval;
 	u32 slottime;
-	u32 acktimeout;
-	u32 ctstimeout;
 	u32 globaltxtimeout;
 
 	/* ANI */

@@ -668,7 +666,7 @@ void ath9k_hw_settsf64(struct ath_hw *ah
 void ath9k_hw_reset_tsf(struct ath_hw *ah);
 void ath9k_hw_set_tsfadjust(struct ath_hw *ah, u32 setting);
 u64 ath9k_hw_extend_tsf(struct ath_hw *ah, u32 rstamp);
-bool ath9k_hw_setslottime(struct ath_hw *ah, u32 us);
+void ath9k_hw_init_global_settings(struct ath_hw *ah);
 void ath9k_hw_set11nmac2040(struct ath_hw *ah);
 void ath9k_hw_beaconinit(struct ath_hw *ah, u32 next_beacon, u32 beacon_period);
 void ath9k_hw_set_sta_beacon_timers(struct ath_hw *ah,
drivers/net/wireless/ath/ath9k/beacon.c +2 -1
@@ -480,7 +480,8 @@ void ath_beacon_tasklet(unsigned long da
 		sc->beacon.updateslot = COMMIT; /* commit next beacon */
 		sc->beacon.slotupdate = slot;
 	} else if (sc->beacon.updateslot == COMMIT && sc->beacon.slotupdate == slot) {
-		ath9k_hw_setslottime(sc->sc_ah, sc->beacon.slottime);
+		ah->slottime = sc->beacon.slottime;
+		ath9k_hw_init_global_settings(ah);
 		sc->beacon.updateslot = OK;
 	}
 	if (bfaddr != 0) {
author
#2 lore raw

PATCH 3/3 ath9k: implement coverage class support

Signed-off-by Felix Fietkau <[email protected]>

---

drivers/net/wireless/ath/ath9k/hw.c +5 -2
@@ -1211,6 +1211,7 @@ void ath9k_hw_init_global_settings(struc
 {
 	struct ieee80211_conf *conf = &ath9k_hw_common(ah)->hw->conf;
 	int acktimeout;
+	int slottime;
 	int sifstime;
 
 	ath_print(ath9k_hw_common(ah), ATH_DBG_RESET, "ah->misc_mode 0x%x\n",

@@ -1225,8 +1226,10 @@ void ath9k_hw_init_global_settings(struc
 	else
 		sifstime = 10;
 
-	acktimeout = ah->slottime + sifstime;
-	ath9k_hw_setslottime(ah, ah->slottime);
+	/* As defined by IEEE 802.11-2007 17.3.8.6 */
+	slottime = ah->slottime + 3 * ah->coverage_class;
+	acktimeout = slottime + sifstime;
+	ath9k_hw_setslottime(ah, slottime);
 	ath9k_hw_set_ack_timeout(ah, acktimeout);
 	ath9k_hw_set_cts_timeout(ah, acktimeout);
 	if (ah->globaltxtimeout != (u32) -1)
drivers/net/wireless/ath/ath9k/hw.h +1 -0
@@ -551,6 +551,7 @@ struct ath_hw {
 	u32 *bank6Temp;
 
 	int16_t txpower_indexoffset;
+	int coverage_class;
 	u32 beacon_interval;
 	u32 slottime;
 	u32 globaltxtimeout;
drivers/net/wireless/ath/ath9k/main.c +1 -0
@@ -2015,6 +2015,18 @@ static void ath9k_sw_scan_complete(struc
 	mutex_unlock(&sc->mutex);
 }
 
+static void ath9k_set_coverage_class(struct ieee80211_hw *hw, u8

coverage_class)
+{
+ struct ath_wiphy *aphy = hw->priv;
+ struct ath_softc *sc = aphy->sc;
+ struct ath_hw *ah = sc->sc_ah;
+
+ mutex_lock(&sc->mutex);
+ ah->coverage_class = coverage_class;
+ ath9k_hw_init_global_settings(ah);
+ mutex_unlock(&sc->mutex);
+}
+
struct ieee80211_ops ath9k_ops = {
.tx = ath9k_tx,
.start = ath9k_start,
@@ -2034,4 +2046,5 @@ struct ieee80211_ops ath9k_ops = {

 	.sw_scan_start      = ath9k_sw_scan_start,
 	.sw_scan_complete   = ath9k_sw_scan_complete,
 	.rfkill_poll        = ath9k_rfkill_poll_state,

+ .set_coverage_class = ath9k_set_coverage_class,
};

author
#3 lore raw

PATCH v2 1/3 mac80211: force use_short_slot=true for 5GHz

In reply to Felix Fietkau

Normally 5GHz does not have a concept of long vs short slot time, however the slot time that it ends up using is the same as for 2.4 GHZ and use_short_slot == true
Because of that, it makes more sense to force use_short_slot = true whenever 5 GHz is being used, so that this particular check does not have to be in every single driver that uses this flag.

Signed-off-by Felix Fietkau <[email protected]>

---
v2: sorry, forgot one chunk of the patch

net/mac80211/mlme.c +2 -0
@@ -670,6 +670,8 @@ static u32 ieee80211_handle_bss_capabili
 	}
 
 	use_short_slot = !!(capab & WLAN_CAPABILITY_SHORT_SLOT_TIME);
+	if (sdata->local->hw.conf.channel->band == IEEE80211_BAND_5GHZ)
+		use_short_slot = true;
 
 	if (use_protection != bss_conf->use_cts_prot) {
 		bss_conf->use_cts_prot = use_protection;
net/mac80211/cfg.c +7 -0
@@ -1087,6 +1087,13 @@ static int ieee80211_change_bss(struct w
 			params->use_short_preamble;
 		changed |= BSS_CHANGED_ERP_PREAMBLE;
 	}
+
+	if (!sdata->vif.bss_conf.use_short_slot &&
+	    sdata->local->hw.conf.channel->band == IEEE80211_BAND_5GHZ) {
+		sdata->vif.bss_conf.use_short_slot = true;
+		changed |= BSS_CHANGED_ERP_SLOT;
+	}
+
 	if (params->use_short_slot_time >= 0) {
 		sdata->vif.bss_conf.use_short_slot =
 			params->use_short_slot_time;