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 <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 55 insertions, 75 deletions

diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index 1660ef17aaf5..422454fe4ff0 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -480,7 +480,8 @@ void ath_beacon_tasklet(unsigned long data)
                 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) {
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 2311fe7a0bf2..e1fd4cc9fae2 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -52,28 +52,6 @@ module_exit(ath9k_exit);
 /* Helper Functions */
 /********************/
 
-static u32 ath9k_hw_mac_usec(struct ath_hw *ah, u32 clks)
-{
-        struct ieee80211_conf *conf = &ath9k_hw_common(ah)->hw->conf;
-
-        if (!ah->curchan) /* should really check for CCK instead */
-                return clks / ATH9K_CLOCK_RATE_CCK;
-        if (conf->channel->band == IEEE80211_BAND_2GHZ)
-                return clks / ATH9K_CLOCK_RATE_2GHZ_OFDM;
-
-        return clks / ATH9K_CLOCK_RATE_5GHZ_OFDM;
-}
-
-static u32 ath9k_hw_mac_to_usec(struct ath_hw *ah, u32 clks)
-{
-        struct ieee80211_conf *conf = &ath9k_hw_common(ah)->hw->conf;
-
-        if (conf_is_ht40(conf))
-                return ath9k_hw_mac_usec(ah, clks) / 2;
-        else
-                return ath9k_hw_mac_usec(ah, clks);
-}
-
 static u32 ath9k_hw_mac_clks(struct ath_hw *ah, u32 usecs)
 {
         struct ieee80211_conf *conf = &ath9k_hw_common(ah)->hw->conf;
@@ -413,8 +391,6 @@ static void ath9k_hw_init_defaults(struct ath_hw *ah)
         ah->beacon_interval = 100;
         ah->enable_32kHz_clock = DONT_USE_32KHZ;
         ah->slottime = (u32) -1;
-        ah->acktimeout = (u32) -1;
-        ah->ctstimeout = (u32) -1;
         ah->globaltxtimeout = (u32) -1;
         ah->power_mode = ATH9K_PM_UNDEFINED;
 }
@@ -1180,34 +1156,25 @@ static void ath9k_hw_init_interrupt_masks(struct ath_hw *ah,
         }
 }
 
-static bool ath9k_hw_set_ack_timeout(struct ath_hw *ah, u32 us)
+static void ath9k_hw_setslottime(struct ath_hw *ah, u32 us)
 {
-        if (us > ath9k_hw_mac_to_usec(ah, MS(0xffffffff, AR_TIME_OUT_ACK))) {
-                ath_print(ath9k_hw_common(ah), ATH_DBG_RESET,
-                          "bad ack timeout %u\n", us);
-                ah->acktimeout = (u32) -1;
-                return false;
-        } else {
-                REG_RMW_FIELD(ah, AR_TIME_OUT,
-                              AR_TIME_OUT_ACK, ath9k_hw_mac_to_clks(ah, us));
-                ah->acktimeout = us;
-                return true;
-        }
+        u32 val = ath9k_hw_mac_to_clks(ah, us);
+        val = min(val, (u32) 0xFFFF);
+        REG_WRITE(ah, AR_D_GBL_IFS_SLOT, val);
 }
 
-static bool ath9k_hw_set_cts_timeout(struct ath_hw *ah, u32 us)
+static void ath9k_hw_set_ack_timeout(struct ath_hw *ah, u32 us)
 {
-        if (us > ath9k_hw_mac_to_usec(ah, MS(0xffffffff, AR_TIME_OUT_CTS))) {
-                ath_print(ath9k_hw_common(ah), ATH_DBG_RESET,
-                          "bad cts timeout %u\n", us);
-                ah->ctstimeout = (u32) -1;
-                return false;
-        } else {
-                REG_RMW_FIELD(ah, AR_TIME_OUT,
-                              AR_TIME_OUT_CTS, ath9k_hw_mac_to_clks(ah, us));
-                ah->ctstimeout = us;
-                return true;
-        }
+        u32 val = ath9k_hw_mac_to_clks(ah, us);
+        val = min(val, (u32) MS(0xFFFFFFFF, AR_TIME_OUT_ACK));
+        REG_RMW_FIELD(ah, AR_TIME_OUT, AR_TIME_OUT_ACK, val);
+}
+
+static void ath9k_hw_set_cts_timeout(struct ath_hw *ah, u32 us)
+{
+        u32 val = ath9k_hw_mac_to_clks(ah, us);
+        val = min(val, (u32) MS(0xFFFFFFFF, AR_TIME_OUT_CTS));
+        REG_RMW_FIELD(ah, AR_TIME_OUT, AR_TIME_OUT_CTS, val);
 }
 
 static bool ath9k_hw_set_global_txtimeout(struct ath_hw *ah, u32 tu)
@@ -1224,23 +1191,32 @@ static bool ath9k_hw_set_global_txtimeout(struct ath_hw *ah, u32 tu)
         }
 }
 
-static void ath9k_hw_init_user_settings(struct ath_hw *ah)
+void ath9k_hw_init_global_settings(struct ath_hw *ah)
 {
+        struct ieee80211_conf *conf = &ath9k_hw_common(ah)->hw->conf;
+        int acktimeout;
+        int sifstime;
+
         ath_print(ath9k_hw_common(ah), ATH_DBG_RESET, "ah->misc_mode 0x%x\n",
                   ah->misc_mode);
 
         if (ah->misc_mode != 0)
                 REG_WRITE(ah, AR_PCU_MISC,
                           REG_READ(ah, AR_PCU_MISC) | ah->misc_mode);
-        if (ah->slottime != (u32) -1)
-                ath9k_hw_setslottime(ah, ah->slottime);
-        if (ah->acktimeout != (u32) -1)
-                ath9k_hw_set_ack_timeout(ah, ah->acktimeout);
-        if (ah->ctstimeout != (u32) -1)
-                ath9k_hw_set_cts_timeout(ah, ah->ctstimeout);
+
+        if (conf->channel && conf->channel->band == IEEE80211_BAND_5GHZ)
+                sifstime = 16;
+        else
+                sifstime = 10;
+
+        acktimeout = ah->slottime + sifstime;
+        ath9k_hw_setslottime(ah, ah->slottime);
+        ath9k_hw_set_ack_timeout(ah, acktimeout);
+        ath9k_hw_set_cts_timeout(ah, acktimeout);
         if (ah->globaltxtimeout != (u32) -1)
                 ath9k_hw_set_global_txtimeout(ah, ah->globaltxtimeout);
 }
+EXPORT_SYMBOL(ath9k_hw_init_global_settings);
 
 void ath9k_hw_deinit(struct ath_hw *ah)
 {
@@ -2061,7 +2037,7 @@ int ath9k_hw_reset(struct ath_hw *ah, struct ath9k_channel *chan,
         if (ah->caps.hw_caps & ATH9K_HW_CAP_RFSILENT)
                 ath9k_enable_rfkill(ah);
 
-        ath9k_hw_init_user_settings(ah);
+        ath9k_hw_init_global_settings(ah);
 
         if (AR_SREV_9287_12_OR_LATER(ah)) {
                 REG_WRITE(ah, AR_D_GBL_IFS_SIFS,
@@ -3658,21 +3634,6 @@ u64 ath9k_hw_extend_tsf(struct ath_hw *ah, u32 rstamp)
 }
 EXPORT_SYMBOL(ath9k_hw_extend_tsf);
 
-bool ath9k_hw_setslottime(struct ath_hw *ah, u32 us)
-{
-        if (us < ATH9K_SLOT_TIME_9 || us > ath9k_hw_mac_to_usec(ah, 0xffff)) {
-                ath_print(ath9k_hw_common(ah), ATH_DBG_RESET,
-                          "bad slot time %u\n", us);
-                ah->slottime = (u32) -1;
-                return false;
-        } else {
-                REG_WRITE(ah, AR_D_GBL_IFS_SLOT, ath9k_hw_mac_to_clks(ah, us));
-                ah->slottime = us;
-                return true;
-        }
-}
-EXPORT_SYMBOL(ath9k_hw_setslottime);
-
 void ath9k_hw_set11nmac2040(struct ath_hw *ah)
 {
         struct ieee80211_conf *conf = &ath9k_hw_common(ah)->hw->conf;
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 3f0f055ea39b..a7ff07537bc4 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -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, u64 tsf64);
 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,
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index b39c7bc41143..580ecca0182c 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1789,6 +1789,7 @@ static void ath9k_bss_info_changed(struct ieee80211_hw *hw,
         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);
@@ -1824,6 +1825,25 @@ static void ath9k_bss_info_changed(struct ieee80211_hw *hw,
                         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);