[PATCH 2.6 1/9] ixgb: Enabling MSI on a PCI slot (not PCI-X) may not work, so always disable MSI for PCI slots, enable message signalled interrupts on 82597EX based adapters

[Ganesh Venkatesan <ganesh.venkatesan@xxxxxxxxx>]

Signed-off-by: Ganesh Venkatesan <ganesh.venkatesan@xxxxxxxxx>
diff -up net-drivers-2.6/drivers/net/ixgb/ixgb.h 
net-drivers-2.6/drivers/net/ixgb.new/ixgb.h
--- net-drivers-2.6/drivers/net/ixgb/ixgb.h     2005-01-05 17:13:27.000000000 
-0800
+++ net-drivers-2.6/drivers/net/ixgb.new/ixgb.h 2005-01-05 17:13:28.000000000 
-0800
@@ -188,5 +188,9 @@ struct ixgb_adapter {
        /* structs defined in ixgb_hw.h */
        struct ixgb_hw hw;
        struct ixgb_hw_stats stats;
+       uint32_t pci_state[16];
+#ifdef CONFIG_PCI_MSI
+       boolean_t have_msi;
+#endif
 };
 #endif /* _IXGB_H_ */
diff -up net-drivers-2.6/drivers/net/ixgb/ixgb_main.c 
net-drivers-2.6/drivers/net/ixgb.new/ixgb_main.c
--- net-drivers-2.6/drivers/net/ixgb/ixgb_main.c        2005-01-05 
17:13:27.000000000 -0800
+++ net-drivers-2.6/drivers/net/ixgb.new/ixgb_main.c    2005-01-05 
17:13:29.000000000 -0800
@@ -238,6 +238,23 @@ ixgb_up(struct ixgb_adapter *adapter)
        ixgb_configure_rx(adapter);
        ixgb_alloc_rx_buffers(adapter);
 
+#ifdef CONFIG_PCI_MSI
+       {
+       boolean_t pcix = (IXGB_READ_REG(&adapter->hw, STATUS) & 
+                                                 IXGB_STATUS_PCIX_MODE) ? TRUE 
: FALSE;
+       adapter->have_msi = TRUE;
+
+       if (!pcix)
+          adapter->have_msi = FALSE;
+       else if((err = pci_enable_msi(adapter->pdev))) {
+               printk (KERN_ERR
+                "Unable to allocate MSI interrupt Error: %d\n", err);
+               adapter->have_msi = FALSE;
+               /* proceed to try to request regular interrupt */
+       }
+       }
+
+#endif
        if((err = request_irq(adapter->pdev->irq, &ixgb_intr,
                                  SA_SHIRQ | SA_SAMPLE_RANDOM,
                                  netdev->name, netdev)))
@@ -278,6 +278,11 @@ ixgb_down(struct ixgb_adapter *adapter, 
 
        ixgb_irq_disable(adapter);
        free_irq(adapter->pdev->irq, netdev);
+#ifdef CONFIG_PCI_MSI
+       if(adapter->have_msi == TRUE)
+               pci_disable_msi(adapter->pdev);
+
+#endif
        if(kill_watchdog)
                del_timer_sync(&adapter->watchdog_timer);
        adapter->link_speed = 0;