package/mac80211/patches/408-ath9k-serialize-ath9k_ps_-wakeup-restore-calls.patch

   1 From 7446da6910f1368273a55ca99acba18828306a6e Mon Sep 17 00:00:00 2001
   2 From: Gabor Juhos <juhosg@openwrt.org>
   3 Date: Sun, 21 Jun 2009 16:59:53 +0200
   4 Subject: [PATCH 3/3] ath9k: serialize ath9k_ps_{wakeup,restore} calls
   5
   6 These functions are changing the power mode of the chip, but this may
   7 have unpredictable effects, if another code are trying to set the power
   8 mode via 'ath9k_hw_setpower' in the same time from another context.
   9
  10 Changes-licensed-under: ISC
  11 Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  12 ---
  13  drivers/net/wireless/ath/ath9k/ath9k.h |    2 +-
  14  drivers/net/wireless/ath/ath9k/hw.c    |   42 ++++++++++++++++++++++----------
  15  2 files changed, 30 insertions(+), 14 deletions(-)
  16
  17 --- a/drivers/net/wireless/ath/ath9k/ath9k.h
  18 +++ b/drivers/net/wireless/ath/ath9k/ath9k.h
  19 @@ -561,7 +561,7 @@ struct ath_softc {
  20         u32 keymax;
  21         DECLARE_BITMAP(keymap, ATH_KEYMAX);
  22         u8 splitmic;
  23 -       atomic_t ps_usecount;
  24 +       unsigned long ps_usecount;
  25         enum ath9k_int imask;
  26         enum ath9k_ht_extprotspacing ht_extprotspacing;
  27         enum ath9k_ht_macmode tx_chan_width;
  28 --- a/drivers/net/wireless/ath/ath9k/hw.c
  29 +++ b/drivers/net/wireless/ath/ath9k/hw.c
  30 @@ -2787,23 +2787,39 @@ bool ath9k_hw_setpower(struct ath_hw *ah
  31
  32  void ath9k_ps_wakeup(struct ath_softc *sc)
  33  {
  34 -       if (atomic_inc_return(&sc->ps_usecount) == 1)
  35 -               if (sc->sc_ah->power_mode != ATH9K_PM_AWAKE) {
  36 -                       sc->sc_ah->restore_mode = sc->sc_ah->power_mode;
  37 -                       ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_AWAKE);
  38 -               }
  39 +       unsigned long flags;
  40 +
  41 +       spin_lock_irqsave(&sc->sc_pm_lock, flags);
  42 +       if (++sc->ps_usecount != 1)
  43 +               goto unlock;
  44 +
  45 +       if (sc->sc_ah->power_mode != ATH9K_PM_AWAKE) {
  46 +               sc->sc_ah->restore_mode = sc->sc_ah->power_mode;
  47 +               ath9k_hw_setpower_nolock(sc->sc_ah, ATH9K_PM_AWAKE);
  48 +       }
  49 +
  50 + unlock:
  51 +       spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
  52  }
  53
  54  void ath9k_ps_restore(struct ath_softc *sc)
  55  {
  56 -       if (atomic_dec_and_test(&sc->ps_usecount))
  57 -               if ((sc->hw->conf.flags & IEEE80211_CONF_PS) &&
  58 -                   !(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
  59 -                                     SC_OP_WAIT_FOR_CAB |
  60 -                                     SC_OP_WAIT_FOR_PSPOLL_DATA |
  61 -                                     SC_OP_WAIT_FOR_TX_ACK)))
  62 -                       ath9k_hw_setpower(sc->sc_ah,
  63 -                                         sc->sc_ah->restore_mode);
  64 +       unsigned long flags;
  65 +
  66 +       spin_lock_irqsave(&sc->sc_pm_lock, flags);
  67 +       if (--sc->ps_usecount != 0)
  68 +               goto unlock;
  69 +
  70 +       if ((sc->hw->conf.flags & IEEE80211_CONF_PS) &&
  71 +               !(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
  72 +                               SC_OP_WAIT_FOR_CAB |
  73 +                               SC_OP_WAIT_FOR_PSPOLL_DATA |
  74 +                               SC_OP_WAIT_FOR_TX_ACK)))
  75 +               ath9k_hw_setpower_nolock(sc->sc_ah,
  76 +                                     sc->sc_ah->restore_mode);
  77 +
  78 + unlock:
  79 +       spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
  80  }
  81
  82  /*