irq.c revision 1a9271331ab663f3c7cda78d86b884f2ea86d4d7 
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
12static 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		   dev_name(&parent->dev), 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 */
36enum 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}
60EXPORT_SYMBOL(pci_lost_interrupt);
61