igb: fix legacy mode irq issue

I booted an igb kernel with the option pci=nomsi and instantly noticed
that interrupts no longer worked on my igb device.  I took a look at the
interrupt initialization and quickly discovered a comment stating:

"DO NOT USE EIAME or IAME in legacy mode"

It seemed a bit odd that bits to enable IAM were being set in legacy
interrupt mode, so I dropped out the following parts and interrupts
began working fine again.

[Updated code flow and a nitpick spelling error --Auke]

Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 2 insertions, 7 deletions

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index bff280eff5e3..3480cc72467a 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -439,7 +439,7 @@ static int igb_request_irq(struct igb_adapter *adapter)
                 err = igb_request_msix(adapter);
                 if (!err) {
                         /* enable IAM, auto-mask,
-                         * DO NOT USE EIAME or IAME in legacy mode */
+                         * DO NOT USE EIAM or IAM in legacy mode */
                         wr32(E1000_IAM, IMS_ENABLE_MASK);
                         goto request_done;
                 }
@@ -465,14 +465,9 @@ static int igb_request_irq(struct igb_adapter *adapter)
         err = request_irq(adapter->pdev->irq, &igb_intr, IRQF_SHARED,
                           netdev->name, netdev);
 
-        if (err) {
+        if (err)
                 dev_err(&adapter->pdev->dev, "Error %d getting interrupt\n",
                         err);
-                goto request_done;
-        }
-
-        /* enable IAM, auto-mask */
-        wr32(E1000_IAM, IMS_ENABLE_MASK);
 
 request_done:
         return err;