drivers/pci/irq.c

   1 /*
   2  * PCI IRQ failure handing code
   3  *
   4  * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
   5  */
   6
   7 #include <linux/acpi.h>
   8 #include <linux/device.h>
   9 #include <linux/kernel.h>
  10 #include <linux/pci.h>
  11
  12 static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason)
  13 {
  14         struct pci_dev *parent = to_pci_dev(pdev->dev.parent);
  15
  16         dev_printk(KERN_ERR, &pdev->dev,
  17                    "Potentially misrouted IRQ (Bridge %s %04x:%04x)\n",
  18                    parent->dev.bus_id, parent->vendor, parent->device);
  19         dev_printk(KERN_ERR, &pdev->dev, "%s\n", reason);
  20         dev_printk(KERN_ERR, &pdev->dev, "Please report to linux-kernel@vger.kernel.org\n");
  21         WARN_ON(1);
  22 }
  23
  24 /**
  25  * pci_lost_interrupt - reports a lost PCI interrupt
  26  * @pdev:       device whose interrupt is lost
  27  *
  28  * The primary function of this routine is to report a lost interrupt
  29  * in a standard way which users can recognise (instead of blaming the
  30  * driver).
  31  *
  32  * Returns:
  33  *  a suggestion for fixing it (although the driver is not required to
  34  * act on this).
  35  */
  36 enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev)
  37 {
  38         if (pdev->msi_enabled || pdev->msix_enabled) {
  39                 enum pci_lost_interrupt_reason ret;
  40
  41                 if (pdev->msix_enabled) {
  42                         pci_note_irq_problem(pdev, "MSIX routing failure");
  43                         ret = PCI_LOST_IRQ_DISABLE_MSIX;
  44                 } else {
  45                         pci_note_irq_problem(pdev, "MSI routing failure");
  46                         ret = PCI_LOST_IRQ_DISABLE_MSI;
  47                 }
  48                 return ret;
  49         }
  50 #ifdef CONFIG_ACPI
  51         if (!(acpi_disabled || acpi_noirq)) {
  52                 pci_note_irq_problem(pdev, "Potential ACPI misrouting please reboot with acpi=noirq");
  53                 /* currently no way to fix acpi on the fly */
  54                 return PCI_LOST_IRQ_DISABLE_ACPI;
  55         }
  56 #endif
  57         pci_note_irq_problem(pdev, "unknown cause (not MSI or ACPI)");
  58         return PCI_LOST_IRQ_NO_INFORMATION;
  59 }
  60 EXPORT_SYMBOL(pci_lost_interrupt);