ath9k: Clean Interrupt handling routine

This patch cleans up the ISR, removing a unnecessary do..while
loop, and waking up the chip before getting the pending
interrupts.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index 99a6852..76c58cc 100644 (file)
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -456,133 +456,124 @@ static void ath9k_tasklet(unsigned long data)
        u32 status = sc->intrstatus;
 
        if (status & ATH9K_INT_FATAL) {
-               /* need a chip reset */
                ath_reset(sc, false);
                return;
-       } else {
+       }
 
-               if (status &
-                   (ATH9K_INT_RX | ATH9K_INT_RXEOL | ATH9K_INT_RXORN)) {
-                       spin_lock_bh(&sc->rx.rxflushlock);
-                       ath_rx_tasklet(sc, 0);
-                       spin_unlock_bh(&sc->rx.rxflushlock);
-               }
-               /* XXX: optimize this */
-               if (status & ATH9K_INT_TX)
-                       ath_tx_tasklet(sc);
+       if (status & (ATH9K_INT_RX | ATH9K_INT_RXEOL | ATH9K_INT_RXORN)) {
+               spin_lock_bh(&sc->rx.rxflushlock);
+               ath_rx_tasklet(sc, 0);
+               spin_unlock_bh(&sc->rx.rxflushlock);
        }
 
+       if (status & ATH9K_INT_TX)
+               ath_tx_tasklet(sc);
+
        /* re-enable hardware interrupt */
        ath9k_hw_set_interrupts(sc->sc_ah, sc->imask);
 }
 
 irqreturn_t ath_isr(int irq, void *dev)
 {
+#define SCHED_INTR (                           \
+               ATH9K_INT_FATAL |               \
+               ATH9K_INT_RXORN |               \
+               ATH9K_INT_RXEOL |               \
+               ATH9K_INT_RX |                  \
+               ATH9K_INT_TX |                  \
+               ATH9K_INT_BMISS |               \
+               ATH9K_INT_CST |                 \
+               ATH9K_INT_TSFOOR)
+
        struct ath_softc *sc = dev;
        struct ath_hw *ah = sc->sc_ah;
        enum ath9k_int status;
        bool sched = false;
 
-       do {
-               if (sc->sc_flags & SC_OP_INVALID) {
-                       /*
-                        * The hardware is not ready/present, don't
-                        * touch anything. Note this can happen early
-                        * on if the IRQ is shared.
-                        */
-                       return IRQ_NONE;
-               }
-               if (!ath9k_hw_intrpend(ah)) {   /* shared irq, not for us */
-                       return IRQ_NONE;
-               }
+       /*
+        * The hardware is not ready/present, don't
+        * touch anything. Note this can happen early
+        * on if the IRQ is shared.
+        */
+       if (sc->sc_flags & SC_OP_INVALID)
+               return IRQ_NONE;
 
-               /*
-                * Figure out the reason(s) for the interrupt.  Note
-                * that the hal returns a pseudo-ISR that may include
-                * bits we haven't explicitly enabled so we mask the
-                * value to insure we only process bits we requested.
-                */
-               ath9k_hw_getisr(ah, &status);   /* NB: clears ISR too */
+       ath9k_ps_wakeup(sc);
 
-               status &= sc->imask;    /* discard unasked-for bits */
+       /* shared irq, not for us */
+
+       if (!ath9k_hw_intrpend(ah)) {
+               ath9k_ps_restore(sc);
+               return IRQ_NONE;
+       }
+
+       /*
+        * Figure out the reason(s) for the interrupt.  Note
+        * that the hal returns a pseudo-ISR that may include
+        * bits we haven't explicitly enabled so we mask the
+        * value to insure we only process bits we requested.
+        */
+       ath9k_hw_getisr(ah, &status);   /* NB: clears ISR too */
+       status &= sc->imask;    /* discard unasked-for bits */
+
+       /*
+        * If there are no status bits set, then this interrupt was not
+        * for me (should have been caught above).
+        */
+       if (!status) {
+               ath9k_ps_restore(sc);
+               return IRQ_NONE;
+       }
 
+       /* Cache the status */
+       sc->intrstatus = status;
+
+       if (status & SCHED_INTR)
+               sched = true;
+
+       /*
+        * If a FATAL or RXORN interrupt is received, we have to reset the
+        * chip immediately.
+        */
+       if (status & (ATH9K_INT_FATAL | ATH9K_INT_RXORN))
+               goto chip_reset;
+
+       if (status & ATH9K_INT_SWBA)
+               tasklet_schedule(&sc->bcon_tasklet);
+
+       if (status & ATH9K_INT_TXURN)
+               ath9k_hw_updatetxtriglevel(ah, true);
+
+       if (status & ATH9K_INT_MIB) {
                /*
-                * If there are no status bits set, then this interrupt was not
-                * for me (should have been caught above).
+                * Disable interrupts until we service the MIB
+                * interrupt; otherwise it will continue to
+                * fire.
                 */
-               if (!status)
-                       return IRQ_NONE;
-
-               sc->intrstatus = status;
-               ath9k_ps_wakeup(sc);
+               ath9k_hw_set_interrupts(ah, 0);
+               /*
+                * Let the hal handle the event. We assume
+                * it will clear whatever condition caused
+                * the interrupt.
+                */
+               ath9k_hw_procmibevent(ah, &sc->nodestats);
+               ath9k_hw_set_interrupts(ah, sc->imask);
+       }
 
-               if (status & ATH9K_INT_FATAL) {
-                       /* need a chip reset */
-                       sched = true;
-               } else if (status & ATH9K_INT_RXORN) {
-                       /* need a chip reset */
+       if (status & ATH9K_INT_TIM_TIMER) {
+               if (!(ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP)) {
+                       /* Clear RxAbort bit so that we can
+                        * receive frames */
+                       ath9k_hw_setpower(ah, ATH9K_PM_AWAKE);
+                       ath9k_hw_setrxabort(ah, 0);
                        sched = true;
-               } else {
-                       if (status & ATH9K_INT_SWBA) {
-                               /* schedule a tasklet for beacon handling */
-                               tasklet_schedule(&sc->bcon_tasklet);
-                       }
-                       if (status & ATH9K_INT_RXEOL) {
-                               /*
-                                * NB: the hardware should re-read the link when
-                                *     RXE bit is written, but it doesn't work
-                                *     at least on older hardware revs.
-                                */
-                               sched = true;
-                       }
-
-                       if (status & ATH9K_INT_TXURN)
-                               /* bump tx trigger level */
-                               ath9k_hw_updatetxtriglevel(ah, true);
-                       /* XXX: optimize this */
-                       if (status & ATH9K_INT_RX)
-                               sched = true;
-                       if (status & ATH9K_INT_TX)
-                               sched = true;
-                       if (status & ATH9K_INT_BMISS)
-                               sched = true;
-                       /* carrier sense timeout */
-                       if (status & ATH9K_INT_CST)
-                               sched = true;
-                       if (status & ATH9K_INT_MIB) {
-                               /*
-                                * Disable interrupts until we service the MIB
-                                * interrupt; otherwise it will continue to
-                                * fire.
-                                */
-                               ath9k_hw_set_interrupts(ah, 0);
-                               /*
-                                * Let the hal handle the event. We assume
-                                * it will clear whatever condition caused
-                                * the interrupt.
-                                */
-                               ath9k_hw_procmibevent(ah, &sc->nodestats);
-                               ath9k_hw_set_interrupts(ah, sc->imask);
-                       }
-                       if (status & ATH9K_INT_TIM_TIMER) {
-                               if (!(ah->caps.hw_caps &
-                                     ATH9K_HW_CAP_AUTOSLEEP)) {
-                                       /* Clear RxAbort bit so that we can
-                                        * receive frames */
-                                       ath9k_hw_setpower(ah, ATH9K_PM_AWAKE);
-                                       ath9k_hw_setrxabort(ah, 0);
-                                       sched = true;
-                                       sc->sc_flags |= SC_OP_WAIT_FOR_BEACON;
-                               }
-                       }
-                       if (status & ATH9K_INT_TSFOOR) {
-                               /* FIXME: Handle this interrupt for power save */
-                               sched = true;
-                       }
+                       sc->sc_flags |= SC_OP_WAIT_FOR_BEACON;
                }
-               ath9k_ps_restore(sc);
-       } while (0);
+       }
 
+chip_reset:
+
+       ath9k_ps_restore(sc);
        ath_debug_stat_interrupt(sc, status);
 
        if (sched) {
@@ -592,6 +583,8 @@ irqreturn_t ath_isr(int irq, void *dev)
        }
 
        return IRQ_HANDLED;
+
+#undef SCHED_INTR
 }
 
 static u32 ath_get_extchanmode(struct ath_softc *sc,