[PATCH] sky2: support msi interrupt (revised)
Stephen Hemminger [Mon, 30 Jan 2006 19:38:00 +0000 (11:38 -0800)]
This hardware supports Message Signaled interrupts.
When setting up, use software interrupt to check for bad hardware.

Signed-off-by: Stephen Hemminger <shemminger @osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/net/sky2.c
drivers/net/sky2.h

index 62733a6..8ed4bd1 100644 (file)
@@ -101,6 +101,10 @@ 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) },
@@ -3064,6 +3068,61 @@ 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)
 {
@@ -3184,6 +3243,20 @@ 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) {
@@ -3200,6 +3273,8 @@ 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);
@@ -3242,6 +3317,8 @@ 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);
index 70525ac..fd12c28 100644 (file)
@@ -1841,6 +1841,7 @@ struct sky2_hw {
        struct net_device    *dev[2];
 
        int                  pm_cap;
+       int                  msi;
        u8                   chip_id;
        u8                   chip_rev;
        u8                   copper;