package/kernel/mac80211/patches/311-ath9k-do-not-access-hardware-on-IRQs-during-reset.patch

   1 From: Felix Fietkau <nbd@openwrt.org>
   2 Date: Thu, 13 Nov 2014 18:29:26 +0100
   3 Subject: [PATCH] ath9k: do not access hardware on IRQs during reset
   4
   5 Instead of killing interrupts during reset when the first one happens,
   6 kill them before issuing the reset.
   7 This fixes an easy to reproduce crash with multiple cards sharing the
   8 same IRQ.
   9
  10 Cc: stable@vger.kernel.org
  11 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
  12 ---
  13
  14 --- a/drivers/net/wireless/ath/ath9k/main.c
  15 +++ b/drivers/net/wireless/ath/ath9k/main.c
  16 @@ -512,16 +512,13 @@ irqreturn_t ath_isr(int irq, void *dev)
  17         if (!ah || test_bit(ATH_OP_INVALID, &common->op_flags))
  18                 return IRQ_NONE;
  19
  20 -       /* shared irq, not for us */
  21 +       if (!AR_SREV_9100(ah) && test_bit(ATH_OP_HW_RESET, &common->op_flags))
  22 +               return IRQ_NONE;
  23
  24 +       /* shared irq, not for us */
  25         if (!ath9k_hw_intrpend(ah))
  26                 return IRQ_NONE;
  27
  28 -       if (test_bit(ATH_OP_HW_RESET, &common->op_flags)) {
  29 -               ath9k_hw_kill_interrupts(ah);
  30 -               return IRQ_HANDLED;
  31 -       }
  32 -
  33         /*
  34          * Figure out the reason(s) for the interrupt.  Note
  35          * that the hal returns a pseudo-ISR that may include
  36 @@ -532,6 +529,9 @@ irqreturn_t ath_isr(int irq, void *dev)
  37         ath9k_debug_sync_cause(sc, sync_cause);
  38         status &= ah->imask;    /* discard unasked-for bits */
  39
  40 +       if (AR_SREV_9100(ah) && test_bit(ATH_OP_HW_RESET, &common->op_flags))
  41 +               return IRQ_HANDLED;
  42 +
  43         /*
  44          * If there are no status bits set, then this interrupt was not
  45          * for me (should have been caught above).
  46 @@ -613,6 +613,7 @@ int ath_reset(struct ath_softc *sc, stru
  47         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
  48         int r;
  49
  50 +       ath9k_hw_kill_interrupts(sc->sc_ah);
  51         set_bit(ATH_OP_HW_RESET, &common->op_flags);
  52
  53         ath9k_ps_wakeup(sc);
  54 @@ -633,6 +634,7 @@ void ath9k_queue_reset(struct ath_softc
  55  #ifdef CPTCFG_ATH9K_DEBUGFS
  56         RESET_STAT_INC(sc, type);
  57  #endif
  58 +       ath9k_hw_kill_interrupts(sc->sc_ah);
  59         set_bit(ATH_OP_HW_RESET, &common->op_flags);
  60         ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
  61  }