ath5k: fix slot time handling

Set the slot time based on the mac80211 short slot vs long slot setting
instead of just forcing long slot for all CCK-enabled channels.
This slightly improves 802.11g mode performance in in my tests.

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

3 files changed, 12 insertions, 2 deletions

diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
index a49aeac378c..4bb381cae08 100644
--- a/drivers/net/wireless/ath/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
@@ -1057,6 +1057,7 @@ struct ath5k_hw {
         u8                      ah_coverage_class;
         bool                    ah_ack_bitrate_high;
         u8                      ah_bwmode;
+        bool                    ah_short_slot;
 
         /* Antenna Control */
         u32                     ah_ant_ctl[AR5K_EEPROM_N_MODES][AR5K_ANT_MAX];
diff --git a/drivers/net/wireless/ath/ath5k/mac80211-ops.c b/drivers/net/wireless/ath/ath5k/mac80211-ops.c
index 9be29b728b1..807bd644016 100644
--- a/drivers/net/wireless/ath/ath5k/mac80211-ops.c
+++ b/drivers/net/wireless/ath/ath5k/mac80211-ops.c
@@ -282,6 +282,15 @@ ath5k_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
         if (changes & BSS_CHANGED_BEACON_INT)
                 sc->bintval = bss_conf->beacon_int;
 
+        if (changes & BSS_CHANGED_ERP_SLOT) {
+                int slot_time;
+
+                ah->ah_short_slot = bss_conf->use_short_slot;
+                slot_time = ath5k_hw_get_default_slottime(ah) +
+                            3 * ah->ah_coverage_class;
+                ath5k_hw_set_ifs_intervals(ah, slot_time);
+        }
+
         if (changes & BSS_CHANGED_ASSOC) {
                 avf->assoc = bss_conf->assoc;
                 if (bss_conf->assoc)
diff --git a/drivers/net/wireless/ath/ath5k/pcu.c b/drivers/net/wireless/ath/ath5k/pcu.c
index e342e470fb0..71b60b7c617 100644
--- a/drivers/net/wireless/ath/ath5k/pcu.c
+++ b/drivers/net/wireless/ath/ath5k/pcu.c
@@ -151,9 +151,9 @@ unsigned int ath5k_hw_get_default_slottime(struct ath5k_hw *ah)
                 slot_time = AR5K_INIT_SLOT_TIME_QUARTER_RATE;
                 break;
         case AR5K_BWMODE_DEFAULT:
-                slot_time = AR5K_INIT_SLOT_TIME_DEFAULT;
         default:
-                if (channel->hw_value & CHANNEL_CCK)
+                slot_time = AR5K_INIT_SLOT_TIME_DEFAULT;
+                if ((channel->hw_value & CHANNEL_CCK) && !ah->ah_short_slot)
                         slot_time = AR5K_INIT_SLOT_TIME_B;
                 break;
         }