e1000: Avoid unhandled IRQ

If hardware asserted an interrupt and driver is down,
then there is nothing to do so return IRQ_HANDLED
instead of IRQ_NONE. Returning IRQ_NONE in above
situation causes screaming IRQ on virtual machines.

CC: Andy Gospodarek <gospo@redhat.com>
Signed-off-by: Tushar Dave <tushar.n.dave@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 4ff88a683f61..e332aee386f6 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -3478,9 +3478,17 @@ static irqreturn_t e1000_intr(int irq, void *data)
         struct e1000_hw *hw = &adapter->hw;
         u32 icr = er32(ICR);
 
-        if (unlikely((!icr) || test_bit(__E1000_DOWN, &adapter->flags)))
+        if (unlikely((!icr)))
                 return IRQ_NONE;  /* Not our interrupt */
 
+        /*
+         * we might have caused the interrupt, but the above
+         * read cleared it, and just in case the driver is
+         * down there is nothing to do so return handled
+         */
+        if (unlikely(test_bit(__E1000_DOWN, &adapter->flags)))
+                return IRQ_HANDLED;
+
         if (unlikely(icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC))) {
                 hw->get_link_status = 1;
                 /* guard against interrupt when we're going down */