[PATCH] ib: mthca: Always re-arm EQs in mthca_tavor_interrupt()

We should always re-arm an event queue's interrupt in
mthca_tavor_interrupt() if the corresponding bit is set in the event cause
register (ECR), even if we didn't find any entries in the EQ.  If we don't,
then there's a window where we miss an EQ entry and then get stuck because
we don't get another EQ event.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 11 insertions, 10 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_eq.c b/drivers/infiniband/hw/mthca/mthca_eq.c
index c81fa8e975ef..8dfafda5ed24 100644
--- a/drivers/infiniband/hw/mthca/mthca_eq.c
+++ b/drivers/infiniband/hw/mthca/mthca_eq.c
@@ -396,20 +396,21 @@ static irqreturn_t mthca_tavor_interrupt(int irq, void *dev_ptr, struct pt_regs
                 writel(dev->eq_table.clr_mask, dev->eq_table.clr_int);
 
         ecr = readl(dev->eq_regs.tavor.ecr_base + 4);
-        if (ecr) {
-                writel(ecr, dev->eq_regs.tavor.ecr_base +
-                       MTHCA_ECR_CLR_BASE - MTHCA_ECR_BASE + 4);
+        if (!ecr)
+                return IRQ_NONE;
 
-                for (i = 0; i < MTHCA_NUM_EQ; ++i)
-                        if (ecr & dev->eq_table.eq[i].eqn_mask &&
-                            mthca_eq_int(dev, &dev->eq_table.eq[i])) {
+        writel(ecr, dev->eq_regs.tavor.ecr_base +
+               MTHCA_ECR_CLR_BASE - MTHCA_ECR_BASE + 4);
+
+        for (i = 0; i < MTHCA_NUM_EQ; ++i)
+                if (ecr & dev->eq_table.eq[i].eqn_mask) {
+                        if (mthca_eq_int(dev, &dev->eq_table.eq[i]))
                                 tavor_set_eq_ci(dev, &dev->eq_table.eq[i],
                                                 dev->eq_table.eq[i].cons_index);
-                                tavor_eq_req_not(dev, dev->eq_table.eq[i].eqn);
-                        }
-        }
+                        tavor_eq_req_not(dev, dev->eq_table.eq[i].eqn);
+                }
 
-        return IRQ_RETVAL(ecr);
+        return IRQ_HANDLED;
 }
 
 static irqreturn_t mthca_tavor_msi_x_interrupt(int irq, void *eq_ptr,