xref: /openbmc/linux/drivers/pci/irq.c (revision 1fa6ac37)
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 		   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  */
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);
61