package/madwifi/patches/375-atim_tsf_update.patch

   1 --- a/ath/if_ath.c
   2 +++ b/ath/if_ath.c
   3 @@ -161,6 +161,7 @@ static void ath_beacon_send(struct ath_s
   4  static void ath_beacon_return(struct ath_softc *, struct ath_buf *);
   5  static void ath_beacon_free(struct ath_softc *);
   6  static void ath_beacon_config(struct ath_softc *, struct ieee80211vap *);
   7 +static void ath_hw_beacon_stop(struct ath_softc *sc);
   8  static int ath_desc_alloc(struct ath_softc *);
   9  static void ath_desc_free(struct ath_softc *);
  10  static void ath_desc_swap(struct ath_desc *);
  11 @@ -2793,6 +2794,72 @@ ath_set_ack_bitrate(struct ath_softc *sc
  12         return 1;
  13  }
  14
  15 +static void
  16 +ath_hw_beacon_stop(struct ath_softc *sc)
  17 +{
  18 +       HAL_BEACON_TIMERS btimers;
  19 +
  20 +       btimers.bt_intval = 0;
  21 +       btimers.bt_nexttbtt = 0;
  22 +       btimers.bt_nextdba = 0xffffffff;
  23 +       btimers.bt_nextswba = 0xffffffff;
  24 +       btimers.bt_nextatim = 0;
  25 +
  26 +       ath_hal_setbeacontimers(sc->sc_ah, &btimers);
  27 +}
  28 +
  29 +/* Fix up the ATIM window after TSF resync */
  30 +static int
  31 +ath_hw_check_atim(struct ath_softc *sc, int window, int intval)
  32 +{
  33 +#define AR5K_TIMER0_5210       0x802c  /* Next beacon time register */
  34 +#define AR5K_TIMER0_5211       0x8028
  35 +#define AR5K_TIMER3_5210       0x8038  /* End of ATIM window time register */
  36 +#define AR5K_TIMER3_5211       0x8034
  37 +       struct ath_hal *ah = sc->sc_ah;
  38 +       int dev = sc->sc_ah->ah_macType;
  39 +       unsigned int nbtt, atim;
  40 +       int is_5210 = 0;
  41 +
  42 +       /*
  43 +        * check if the ATIM window is still correct:
  44 +        *   1.) usually ATIM should be NBTT + window
  45 +        *   2.) nbtt already updated
  46 +        *   3.) nbtt already updated and has wrapped around
  47 +        *   4.) atim has wrapped around
  48 +        */
  49 +       switch(dev) {
  50 +       case 5210:
  51 +               nbtt = OS_REG_READ(ah, AR5K_TIMER0_5210);
  52 +               atim = OS_REG_READ(ah, AR5K_TIMER3_5210);
  53 +               is_5210 = 1;
  54 +               break;
  55 +       case 5211:
  56 +       case 5212:
  57 +               nbtt = OS_REG_READ(ah, AR5K_TIMER0_5211);
  58 +               atim = OS_REG_READ(ah, AR5K_TIMER3_5211);
  59 +               break;
  60 +       /* NB: 5416+ doesn't do ATIM in hw */
  61 +       case 5416:
  62 +       default:
  63 +               return 0;
  64 +       }
  65 +
  66 +       if ((atim - nbtt != window) &&                          /* 1.) */
  67 +           (nbtt - atim != intval - window) &&                 /* 2.) */
  68 +           ((nbtt | 0x10000) - atim != intval - window) &&     /* 3.) */
  69 +           ((atim | 0x10000) - nbtt != window)) {              /* 4.) */
  70 +               if (is_5210)
  71 +                       OS_REG_WRITE(ah, AR5K_TIMER3_5210, nbtt + window );
  72 +               else
  73 +                       OS_REG_WRITE(ah, AR5K_TIMER3_5211, nbtt + window );
  74 +               return atim - nbtt;
  75 +       }
  76 +
  77 +       return 0;
  78 +}
  79 +
  80 +
  81  /*
  82   * Reset the hardware w/o losing operational state.  This is
  83   * basically a more efficient way of doing ath_stop, ath_init,
  84 @@ -5292,6 +5359,7 @@ ath_beacon_config(struct ath_softc *sc,
  85         u_int64_t tsf, hw_tsf;
  86         u_int32_t tsftu, hw_tsftu;
  87         u_int32_t intval, nexttbtt = 0;
  88 +       unsigned long flags;
  89         int reset_tsf = 0;
  90
  91         if (vap == NULL)
  92 @@ -5299,6 +5367,9 @@ ath_beacon_config(struct ath_softc *sc,
  93
  94         ni = vap->iv_bss;
  95
  96 +       /* TSF calculation is timing critical - we don't want to be interrupted here */
  97 +       local_irq_save(flags);
  98 +
  99         hw_tsf = ath_hal_gettsf64(ah);
 100         tsf = le64_to_cpu(ni->ni_tstamp.tsf);
 101         hw_tsftu = hw_tsf >> 10;
 102 @@ -5488,15 +5559,27 @@ ath_beacon_config(struct ath_softc *sc,
 103                                 <= ath_hal_sw_beacon_response_time)
 104                         nexttbtt += intval;
 105                 sc->sc_nexttbtt = nexttbtt;
 106 +
 107 +               /* stop beacons before reconfiguring the timers to avoid race
 108 +                * conditions. ath_hal_beaconinit will start them again */
 109 +               ath_hw_beacon_stop(sc);
 110 +
 111                 ath_hal_beaconinit(ah, nexttbtt, intval);
 112                 if (intval & HAL_BEACON_RESET_TSF) {
 113                         sc->sc_last_tsf = 0;
 114                 }
 115                 sc->sc_bmisscount = 0;
 116                 ath_hal_intrset(ah, sc->sc_imask);
 117 +
 118 +               if ((sc->sc_opmode == HAL_M_IBSS) && ath_hw_check_atim(sc, 1, intval & HAL_BEACON_PERIOD)) {
 119 +                       DPRINTF(sc, ATH_DEBUG_BEACON,
 120 +                               "fixed atim window after beacon init\n");
 121 +               }
 122         }
 123
 124  ath_beacon_config_debug:
 125 +       local_irq_restore(flags);
 126 +
 127         /* We print all debug messages here, in order to preserve the
 128          * time critical aspect of this function */
 129         DPRINTF(sc, ATH_DEBUG_BEACON,
 130 @@ -6399,6 +6482,11 @@ ath_recv_mgmt(struct ieee80211vap * vap,
 131                         DPRINTF(sc, ATH_DEBUG_BEACON,
 132                                 "Updated beacon timers\n");
 133                 }
 134 +               if ((sc->sc_opmode == HAL_M_IBSS) &&
 135 +                               IEEE80211_ADDR_EQ(ni->ni_bssid, vap->iv_bss->ni_bssid) &&
 136 +                               ath_hw_check_atim(sc, 1, vap->iv_bss->ni_intval)) {
 137 +                       DPRINTF(sc, ATH_DEBUG_ANY, "Fixed ATIM window after beacon recv\n");
 138 +               }
 139                 /* NB: Fall Through */
 140         case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
 141                 if (vap->iv_opmode == IEEE80211_M_IBSS &&