xref: /openbmc/linux/drivers/pci/irq.c (revision 4f3db074)
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/export.h>
11 #include <linux/pci.h>
12 
13 static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason)
14 {
15 	struct pci_dev *parent = to_pci_dev(pdev->dev.parent);
16 
17 	dev_err(&pdev->dev,
18 		"Potentially misrouted IRQ (Bridge %s %04x:%04x)\n",
19 		dev_name(&parent->dev), parent->vendor, parent->device);
20 	dev_err(&pdev->dev, "%s\n", reason);
21 	dev_err(&pdev->dev, "Please report to linux-kernel@vger.kernel.org\n");
22 	WARN_ON(1);
23 }
24 
25 /**
26  * pci_lost_interrupt - reports a lost PCI interrupt
27  * @pdev:	device whose interrupt is lost
28  *
29  * The primary function of this routine is to report a lost interrupt
30  * in a standard way which users can recognise (instead of blaming the
31  * driver).
32  *
33  * Returns:
34  *  a suggestion for fixing it (although the driver is not required to
35  * act on this).
36  */
37 enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev)
38 {
39 	if (pdev->msi_enabled || pdev->msix_enabled) {
40 		enum pci_lost_interrupt_reason ret;
41 
42 		if (pdev->msix_enabled) {
43 			pci_note_irq_problem(pdev, "MSIX routing failure");
44 			ret = PCI_LOST_IRQ_DISABLE_MSIX;
45 		} else {
46 			pci_note_irq_problem(pdev, "MSI routing failure");
47 			ret = PCI_LOST_IRQ_DISABLE_MSI;
48 		}
49 		return ret;
50 	}
51 #ifdef CONFIG_ACPI
52 	if (!(acpi_disabled || acpi_noirq)) {
53 		pci_note_irq_problem(pdev, "Potential ACPI misrouting please reboot with acpi=noirq");
54 		/* currently no way to fix acpi on the fly */
55 		return PCI_LOST_IRQ_DISABLE_ACPI;
56 	}
57 #endif
58 	pci_note_irq_problem(pdev, "unknown cause (not MSI or ACPI)");
59 	return PCI_LOST_IRQ_NO_INFORMATION;
60 }
61 EXPORT_SYMBOL(pci_lost_interrupt);
62