[PATCH] sky2: remove MSI support

Remove Message Signaled Interrupt support (for 2.6.16).
MSI is inherently edge-triggered and that is incompatiable (without more
work) with NAPI.

In future, will replace with smarter lockless-IRQ handling like
tg3.c

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 0 insertions, 78 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index ca8160d68229..72c1630977d6 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -96,10 +96,6 @@ static int copybreak __read_mostly = 256;
 module_param(copybreak, int, 0);
 MODULE_PARM_DESC(copybreak, "Receive copy threshold");
 
-static int disable_msi = 0;
-module_param(disable_msi, int, 0);
-MODULE_PARM_DESC(disable_msi, "Disable Message Signaled Interrupt (MSI)");
-
 static const struct pci_device_id sky2_id_table[] = {
         { PCI_DEVICE(PCI_VENDOR_ID_SYSKONNECT, 0x9000) },
         { PCI_DEVICE(PCI_VENDOR_ID_SYSKONNECT, 0x9E00) },
@@ -3126,61 +3122,6 @@ static void __devinit sky2_show_addr(struct net_device *dev)
                        dev->dev_addr[3], dev->dev_addr[4], dev->dev_addr[5]);
 }
 
-/* Handle software interrupt used during MSI test */
-static irqreturn_t __devinit sky2_test_intr(int irq, void *dev_id,
-                                            struct pt_regs *regs)
-{
-        struct sky2_hw *hw = dev_id;
-        u32 status = sky2_read32(hw, B0_Y2_SP_ISRC2);
-
-        if (status == 0)
-                return IRQ_NONE;
-
-        if (status & Y2_IS_IRQ_SW) {
-                sky2_write8(hw, B0_CTST, CS_CL_SW_IRQ);
-                hw->msi = 1;
-        }
-        sky2_write32(hw, B0_Y2_SP_ICR, 2);
-
-        sky2_read32(hw, B0_IMSK);
-        return IRQ_HANDLED;
-}
-
-/* Test interrupt path by forcing a a software IRQ */
-static int __devinit sky2_test_msi(struct sky2_hw *hw)
-{
-        struct pci_dev *pdev = hw->pdev;
-        int i, err;
-
-        sky2_write32(hw, B0_IMSK, Y2_IS_IRQ_SW);
-
-        err = request_irq(pdev->irq, sky2_test_intr, SA_SHIRQ, DRV_NAME, hw);
-        if (err) {
-                printk(KERN_ERR PFX "%s: cannot assign irq %d\n",
-                       pci_name(pdev), pdev->irq);
-                return err;
-        }
-
-        sky2_write8(hw, B0_CTST, CS_ST_SW_IRQ);
-        wmb();
-
-        for (i = 0; i < 10; i++) {
-                barrier();
-                if (hw->msi)
-                        goto found;
-                mdelay(1);
-        }
-
-        err = -EOPNOTSUPP;
-        sky2_write8(hw, B0_CTST, CS_CL_SW_IRQ);
- found:
-        sky2_write32(hw, B0_IMSK, 0);
-
-        free_irq(pdev->irq, hw);
-
-        return err;
-}
-
 static int __devinit sky2_probe(struct pci_dev *pdev,
                                 const struct pci_device_id *ent)
 {
@@ -3302,20 +3243,6 @@ static int __devinit sky2_probe(struct pci_dev *pdev,
                 }
         }
 
-        if (!disable_msi && pci_enable_msi(pdev) == 0) {
-                err = sky2_test_msi(hw);
-                if (err == -EOPNOTSUPP) {
-                        /* MSI test failed, go back to INTx mode */
-                        printk(KERN_WARNING PFX "%s: No interrupt was generated using MSI, "
-                               "switching to INTx mode. Please report this failure to "
-                               "the PCI maintainer and include system chipset information.\n",
-                               pci_name(pdev));
-                        pci_disable_msi(pdev);
-                }
-                else if (err)
-                        goto err_out_unregister;
-        }
-
         err = request_irq(pdev->irq, sky2_intr, SA_SHIRQ | SA_SAMPLE_RANDOM,
                           DRV_NAME, hw);
         if (err) {
@@ -3332,8 +3259,6 @@ static int __devinit sky2_probe(struct pci_dev *pdev,
         return 0;
 
 err_out_unregister:
-        if (hw->msi)
-                pci_disable_msi(pdev);
         if (dev1) {
                 unregister_netdev(dev1);
                 free_netdev(dev1);
@@ -3376,8 +3301,6 @@ static void __devexit sky2_remove(struct pci_dev *pdev)
         sky2_read8(hw, B0_CTST);
 
         free_irq(pdev->irq, hw);
-        if (hw->msi)
-                pci_disable_msi(pdev);
         pci_free_consistent(pdev, STATUS_LE_BYTES, hw->st_le, hw->st_dma);
         pci_release_regions(pdev);
         pci_disable_device(pdev);
diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h
index 3edb98075e0a..dce955c76f3c 100644
--- a/drivers/net/sky2.h
+++ b/drivers/net/sky2.h
@@ -1881,7 +1881,6 @@ struct sky2_hw {
         u32                  intr_mask;
 
         int                  pm_cap;
-        int                  msi;
         u8                   chip_id;
         u8                   chip_rev;
         u8                   copper;