[net-2.6 PATCH] igb: make certain to reassign legacy interrupt vectors after reset

[net-2.6 PATCH] igb: make certain to reassign legacy interrupt vectors after reset

[Jeff Kirsher]

From: Alexander Duyck <alexander.h.duyck@intel.com>

This change corrects an issue that will cause false hangs when using either
82575 or 82580 in legacy interrupt mode.  The issue is caused when there is
a slow traffic flow and an "ethtool -r" is executed while using legacy or
MSI interrupts.  MSI-X is not affected by this issue due to the fact that
we were already reconfiguring the vectors after reset.

If possible it would be best to push this for net-2.6 since it is resolving
a bug but if that is not possible then net-next-2.6 will be fine.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---

 drivers/net/igb/igb_main.c |   20 +++++---------------
 1 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 997124d..c881347 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -421,6 +421,8 @@ static void igb_assign_vector(struct igb_q_vector *q_vector, int msix_vector)
 			msixbm = E1000_EICR_RX_QUEUE0 << rx_queue;
 		if (tx_queue > IGB_N0_QUEUE)
 			msixbm |= E1000_EICR_TX_QUEUE0 << tx_queue;
+		if (!adapter->msix_entries && msix_vector == 0)
+			msixbm |= E1000_EIMS_OTHER;
 		array_wr32(E1000_MSIXBM(0), msix_vector, msixbm);
 		q_vector->eims_value = msixbm;
 		break;
@@ -877,7 +879,6 @@ static int igb_request_irq(struct igb_adapter *adapter)
 {
 	struct net_device *netdev = adapter->netdev;
 	struct pci_dev *pdev = adapter->pdev;
-	struct e1000_hw *hw = &adapter->hw;
 	int err = 0;
 
 	if (adapter->msix_entries) {
@@ -909,20 +910,7 @@ static int igb_request_irq(struct igb_adapter *adapter)
 		igb_setup_all_tx_resources(adapter);
 		igb_setup_all_rx_resources(adapter);
 	} else {
-		switch (hw->mac.type) {
-		case e1000_82575:
-			wr32(E1000_MSIXBM(0),
-			     (E1000_EICR_RX_QUEUE0 |
-			      E1000_EICR_TX_QUEUE0 |
-			      E1000_EIMS_OTHER));
-			break;
-		case e1000_82580:
-		case e1000_82576:
-			wr32(E1000_IVAR0, E1000_IVAR_VALID);
-			break;
-		default:
-			break;
-		}
+		igb_assign_vector(adapter->q_vector[0], 0);
 	}
 
 	if (adapter->flags & IGB_FLAG_HAS_MSI) {
@@ -1140,6 +1128,8 @@ int igb_up(struct igb_adapter *adapter)
 	}
 	if (adapter->msix_entries)
 		igb_configure_msix(adapter);
+	else
+		igb_assign_vector(adapter->q_vector[0], 0);
 
 	/* Clear any pending interrupts. */
 	rd32(E1000_ICR);

Re: [net-2.6 PATCH] igb: make certain to reassign legacy interrupt vectors after reset

[David Miller]

From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Date: Wed, 03 Feb 2010 23:59:51 -0800

> From: Alexander Duyck <alexander.h.duyck@intel.com>
> 
> This change corrects an issue that will cause false hangs when using either
> 82575 or 82580 in legacy interrupt mode.  The issue is caused when there is
> a slow traffic flow and an "ethtool -r" is executed while using legacy or
> MSI interrupts.  MSI-X is not affected by this issue due to the fact that
> we were already reconfiguring the vectors after reset.
> 
> If possible it would be best to push this for net-2.6 since it is resolving
> a bug but if that is not possible then net-next-2.6 will be fine.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Applied, thanks.