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authorJames Bottomley <James.Bottomley@HansenPartnership.com>2008-08-03 14:02:12 -0400
committerJesse Barnes <jbarnes@virtuousgeek.org>2008-10-23 17:54:18 -0400
commit388c8c16abafc2e74dff173b5de9ee519ea8d32f (patch)
treeed1197dcbff33881b7e285c066f1e4260be6c7a4 /drivers/pci/irq.c
parent18b341b76cd99ce949806ccf5565900465ec2e7f (diff)
PCI: add routines for debugging and handling lost interrupts
We're getting a lot of storage drivers blamed for interrupt misrouting issues. This patch provides a standard way of reporting the problem ... and, if possible, correcting it. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/irq.c')
-rw-r--r--drivers/pci/irq.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c
new file mode 100644
index 000000000000..6441dfa969a3
--- /dev/null
+++ b/drivers/pci/irq.c
@@ -0,0 +1,60 @@
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 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 */
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);