ath9k: Use atomic reference count for interrupt ops

Let us enable/disable interrupts based on reference count.
By doing this we can ensure that interrupts are never be
enabled in the middle of tasklet processing. Instead of
addressing corner cases like "ath9k: avoid enabling interrupts
while processing rx", this approach handles it in generic manner.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath9k/mac.c b/drivers/net/wireless/ath/ath9k/mac.c
index c3af61e38bd5..0f90e1521ffe 100644
--- a/drivers/net/wireless/ath/ath9k/mac.c
+++ b/drivers/net/wireless/ath/ath9k/mac.c
@@ -800,6 +800,11 @@ void ath9k_hw_disable_interrupts(struct ath_hw *ah)
 {
         struct ath_common *common = ath9k_hw_common(ah);
 
+        if (!(ah->imask & ATH9K_INT_GLOBAL))
+                atomic_set(&ah->intr_ref_cnt, -1);
+        else
+                atomic_dec(&ah->intr_ref_cnt);
+
         ath_dbg(common, ATH_DBG_INTERRUPT, "disable IER\n");
         REG_WRITE(ah, AR_IER, AR_IER_DISABLE);
         (void) REG_READ(ah, AR_IER);
@@ -821,6 +826,13 @@ void ath9k_hw_enable_interrupts(struct ath_hw *ah)
         if (!(ah->imask & ATH9K_INT_GLOBAL))
                 return;
 
+        if (!atomic_inc_and_test(&ah->intr_ref_cnt)) {
+                ath_dbg(common, ATH_DBG_INTERRUPT,
+                        "Do not enable IER ref count %d\n",
+                        atomic_read(&ah->intr_ref_cnt));
+                return;
+        }
+
         if (AR_SREV_9340(ah))
                 sync_default &= ~AR_INTR_SYNC_HOST1_FATAL;
 
@@ -852,7 +864,6 @@ void ath9k_hw_set_interrupts(struct ath_hw *ah, enum ath9k_int ints)
 
         ath_dbg(common, ATH_DBG_INTERRUPT, "0x%x => 0x%x\n", omask, ints);
 
-        /* TODO: global int Ref count */
         mask = ints & ATH9K_INT_COMMON;
         mask2 = 0;