bna: fix interrupt handling

This fix handles the case when IRQ handler is called (for shared IRQs)
even before the driver is ready to handle interrupts.

Signed-off-by: Debashis Dutt <ddutt@brocade.com>
Signed-off-by: Rasesh Mody <rmody@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 21 deletions

diff --git a/drivers/net/bna/bnad.c b/drivers/net/bna/bnad.c
index e380c0e88f4f..7210c34d2d5b 100644
--- a/drivers/net/bna/bnad.c
+++ b/drivers/net/bna/bnad.c
@@ -564,9 +564,11 @@ bnad_disable_rx_irq(struct bnad *bnad, struct bna_ccb *ccb)
 static void
 bnad_enable_rx_irq(struct bnad *bnad, struct bna_ccb *ccb)
 {
-        spin_lock_irq(&bnad->bna_lock); /* Because of polling context */
+        unsigned long flags;
+
+        spin_lock_irqsave(&bnad->bna_lock, flags); /* Because of polling context */
         bnad_enable_rx_irq_unsafe(ccb);
-        spin_unlock_irq(&bnad->bna_lock);
+        spin_unlock_irqrestore(&bnad->bna_lock, flags);
 }
 
 static void
@@ -599,7 +601,7 @@ static irqreturn_t
 bnad_msix_mbox_handler(int irq, void *data)
 {
         u32 intr_status;
-        unsigned long  flags;
+        unsigned long flags;
         struct net_device *netdev = data;
         struct bnad *bnad;
 
@@ -630,13 +632,15 @@ bnad_isr(int irq, void *data)
         struct bnad_rx_info *rx_info;
         struct bnad_rx_ctrl *rx_ctrl;
 
-        spin_lock_irqsave(&bnad->bna_lock, flags);
+        if (unlikely(test_bit(BNAD_RF_MBOX_IRQ_DISABLED, &bnad->run_flags)))
+                return IRQ_NONE;
 
         bna_intr_status_get(&bnad->bna, intr_status);
-        if (!intr_status) {
-                spin_unlock_irqrestore(&bnad->bna_lock, flags);
+
+        if (unlikely(!intr_status))
                 return IRQ_NONE;
-        }
+
+        spin_lock_irqsave(&bnad->bna_lock, flags);
 
         if (BNA_IS_MBOX_ERR_INTR(intr_status)) {
                 bna_mbox_handler(&bnad->bna, intr_status);
@@ -672,11 +676,10 @@ bnad_enable_mbox_irq(struct bnad *bnad)
 {
         int irq = BNAD_GET_MBOX_IRQ(bnad);
 
-        if (!(bnad->cfg_flags & BNAD_CF_MSIX))
-                return;
-
         if (test_and_clear_bit(BNAD_RF_MBOX_IRQ_DISABLED, &bnad->run_flags))
-                enable_irq(irq);
+                if (bnad->cfg_flags & BNAD_CF_MSIX)
+                        enable_irq(irq);
+
         BNAD_UPDATE_CTR(bnad, mbox_intr_enabled);
 }
 
@@ -689,11 +692,11 @@ bnad_disable_mbox_irq(struct bnad *bnad)
 {
         int irq = BNAD_GET_MBOX_IRQ(bnad);
 
-        if (!(bnad->cfg_flags & BNAD_CF_MSIX))
-                return;
 
         if (!test_and_set_bit(BNAD_RF_MBOX_IRQ_DISABLED, &bnad->run_flags))
-                disable_irq_nosync(irq);
+                if (bnad->cfg_flags & BNAD_CF_MSIX)
+                        disable_irq_nosync(irq);
+
         BNAD_UPDATE_CTR(bnad, mbox_intr_disabled);
 }
 
@@ -1045,14 +1048,12 @@ bnad_mbox_irq_free(struct bnad *bnad,
                 return;
 
         spin_lock_irqsave(&bnad->bna_lock, flags);
-
         bnad_disable_mbox_irq(bnad);
+        spin_unlock_irqrestore(&bnad->bna_lock, flags);
 
         irq = BNAD_GET_MBOX_IRQ(bnad);
         free_irq(irq, bnad->netdev);
 
-        spin_unlock_irqrestore(&bnad->bna_lock, flags);
-
         kfree(intr_info->idl);
 }
 
@@ -1094,8 +1095,15 @@ bnad_mbox_irq_alloc(struct bnad *bnad,
 
         sprintf(bnad->mbox_irq_name, "%s", BNAD_NAME);
 
+        /*
+         * Set the Mbox IRQ disable flag, so that the IRQ handler
+         * called from request_irq() for SHARED IRQs do not execute
+         */
+        set_bit(BNAD_RF_MBOX_IRQ_DISABLED, &bnad->run_flags);
+
         err = request_irq(irq, irq_handler, flags,
                           bnad->mbox_irq_name, bnad->netdev);
+
         if (err) {
                 kfree(intr_info->idl);
                 intr_info->idl = NULL;
@@ -1103,7 +1111,8 @@ bnad_mbox_irq_alloc(struct bnad *bnad,
         }
 
         spin_lock_irqsave(&bnad->bna_lock, flags);
-        bnad_disable_mbox_irq(bnad);
+        if (bnad->cfg_flags & BNAD_CF_MSIX)
+                disable_irq_nosync(irq);
         spin_unlock_irqrestore(&bnad->bna_lock, flags);
         return 0;
 }
@@ -1485,7 +1494,6 @@ bnad_stats_timer_start(struct bnad *bnad)
                           jiffies + msecs_to_jiffies(BNAD_STATS_TIMER_FREQ));
         }
         spin_unlock_irqrestore(&bnad->bna_lock, flags);
-
 }
 
 /*
@@ -2170,7 +2178,6 @@ bnad_device_disable(struct bnad *bnad)
         spin_unlock_irqrestore(&bnad->bna_lock, flags);
 
         wait_for_completion(&bnad->bnad_completions.ioc_comp);
-
 }
 
 static int
@@ -3108,7 +3115,6 @@ bnad_pci_probe(struct pci_dev *pdev,
 
         spin_lock_irqsave(&bnad->bna_lock, flags);
         bna_init(bna, bnad, &pcidev_info, &bnad->res_info[0]);
-
         spin_unlock_irqrestore(&bnad->bna_lock, flags);
 
         bnad->stats.bna_stats = &bna->stats;