ath5k: fix short preamble rate duration value

Subtract the difference in preamble duration (in usec) from the value
returned by ieee80211_generic_frame_duration.

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

diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
index 8a06dbd..996d8af 100644 (file)
--- a/drivers/net/wireless/ath/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
@@ -1233,7 +1233,7 @@ int ath5k_eeprom_read_mac(struct ath5k_hw *ah, u8 *mac);
 /* Protocol Control Unit Functions */
 /* Helpers */
 int ath5k_hw_get_frame_duration(struct ath5k_hw *ah,
-               int len, struct ieee80211_rate *rate);
+               int len, struct ieee80211_rate *rate, bool shortpre);
 unsigned int ath5k_hw_get_default_slottime(struct ath5k_hw *ah);
 unsigned int ath5k_hw_get_default_sifs(struct ath5k_hw *ah);
 extern int ath5k_hw_set_opmode(struct ath5k_hw *ah, enum nl80211_iftype opmode);

diff --git a/drivers/net/wireless/ath/ath5k/pcu.c b/drivers/net/wireless/ath/ath5k/pcu.c
index a702817..e342e47 100644 (file)
--- a/drivers/net/wireless/ath/ath5k/pcu.c
+++ b/drivers/net/wireless/ath/ath5k/pcu.c
@@ -75,7 +75,7 @@ static const unsigned int ack_rates_high[] =
  * bwmodes.
  */
 int ath5k_hw_get_frame_duration(struct ath5k_hw *ah,
-               int len, struct ieee80211_rate *rate)
+               int len, struct ieee80211_rate *rate, bool shortpre)
 {
        struct ath5k_softc *sc = ah->ah_sc;
        int sifs, preamble, plcp_bits, sym_time;
@@ -84,9 +84,15 @@ int ath5k_hw_get_frame_duration(struct ath5k_hw *ah,
 
        /* Fallback */
        if (!ah->ah_bwmode) {
-               dur = ieee80211_generic_frame_duration(sc->hw,
-                                               NULL, len, rate);
-               return le16_to_cpu(dur);
+               __le16 raw_dur = ieee80211_generic_frame_duration(sc->hw,
+                                       NULL, len, rate);
+
+               /* subtract difference between long and short preamble */
+               dur = le16_to_cpu(raw_dur);
+               if (shortpre)
+                       dur -= 96;
+
+               return dur;
        }
 
        bitrate = rate->bitrate;
@@ -263,27 +269,14 @@ static inline void ath5k_hw_write_rate_duration(struct ath5k_hw *ah)
                 * actual rate for this rate. See mac80211 tx.c
                 * ieee80211_duration() for a brief description of
                 * what rate we should choose to TX ACKs. */
-               tx_time = ath5k_hw_get_frame_duration(ah, 10, rate);
+               tx_time = ath5k_hw_get_frame_duration(ah, 10, rate, false);
 
                ath5k_hw_reg_write(ah, tx_time, reg);
 
                if (!(rate->flags & IEEE80211_RATE_SHORT_PREAMBLE))
                        continue;
 
-               /*
-                * We're not distinguishing short preamble here,
-                * This is true, all we'll get is a longer value here
-                * which is not necessarilly bad. We could use
-                * export ieee80211_frame_duration() but that needs to be
-                * fixed first to be properly used by mac802111 drivers:
-                *
-                *  - remove erp stuff and let the routine figure ofdm
-                *    erp rates
-                *  - remove passing argument ieee80211_local as
-                *    drivers don't have access to it
-                *  - move drivers using ieee80211_generic_frame_duration()
-                *    to this
-                */
+               tx_time = ath5k_hw_get_frame_duration(ah, 10, rate, true);
                ath5k_hw_reg_write(ah, tx_time,
                        reg + (AR5K_SET_SHORT_PREAMBLE << 2));
        }

diff --git a/drivers/net/wireless/ath/ath5k/qcu.c b/drivers/net/wireless/ath/ath5k/qcu.c
index 3343fb9..93abcfa 100644 (file)
--- a/drivers/net/wireless/ath/ath5k/qcu.c
+++ b/drivers/net/wireless/ath/ath5k/qcu.c
@@ -550,7 +550,7 @@ int ath5k_hw_set_ifs_intervals(struct ath5k_hw *ah, unsigned int slot_time)
        else
                rate = &sc->sbands[IEEE80211_BAND_2GHZ].bitrates[0];
 
-       ack_tx_time = ath5k_hw_get_frame_duration(ah, 10, rate);
+       ack_tx_time = ath5k_hw_get_frame_duration(ah, 10, rate, false);
 
        /* ack_tx_time includes an SIFS already */
        eifs = ack_tx_time + sifs + 2 * slot_time;