[PATCH] forcedeth: Disable INTx when enabling MSI in forcedeth

At least some nforce cards continue to send legacy interrupts when MSI
is enabled, and these interrupts are treated as unhandled by the
kernel. This patch disables legacy interrupts explicitly when enabling
MSI mode.

The correct fix is to change the MSI infrastructure to disable legacy
interrupts when enabling MSI, but this is potentially risky if the
device isn't PCI-2.3 or is quirky, so the correct fix is going into
mainline, while patches like this one go into -stable.

Legend has it that it is most correct to disable legacy interrupts
before enabling MSI, but the mainline patch does it in the other
order, and this patch is "obviously" the same as mainline.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index 11b8f1b43dd5994a255c1b6613d0cfa868a4bdeb..bacd25f452a95624553770c8d215507a5aedf932 100644 (file)
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -2692,11 +2692,13 @@ static int nv_request_irq(struct net_device *dev, int intr_test)
        }
        if (ret != 0 && np->msi_flags & NV_MSI_CAPABLE) {
                if ((ret = pci_enable_msi(np->pci_dev)) == 0) {
+                       pci_intx(np->pci_dev, 0);
                        np->msi_flags |= NV_MSI_ENABLED;
                        if ((!intr_test && request_irq(np->pci_dev->irq, &nv_nic_irq, IRQF_SHARED, dev->name, dev) != 0) ||
                            (intr_test && request_irq(np->pci_dev->irq, &nv_nic_irq_test, IRQF_SHARED, dev->name, dev) != 0)) {
                                printk(KERN_INFO "forcedeth: request_irq failed %d\n", ret);
                                pci_disable_msi(np->pci_dev);
+                               pci_intx(np->pci_dev, 1);
                                np->msi_flags &= ~NV_MSI_ENABLED;
                                goto out_err;
                        }
@@ -2739,6 +2741,7 @@ static void nv_free_irq(struct net_device *dev)
                free_irq(np->pci_dev->irq, dev);
                if (np->msi_flags & NV_MSI_ENABLED) {
                        pci_disable_msi(np->pci_dev);
+                       pci_intx(np->pci_dev, 1);
                        np->msi_flags &= ~NV_MSI_ENABLED;
                }
        }