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PCI: add routines for debugging and handling lost interrupts

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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>
This commit is contained in:
James Bottomley 2008-08-03 13:02:12 -05:00 committed by Jesse Barnes
parent 18b341b76c
commit 388c8c16ab
3 changed files with 69 additions and 1 deletions
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3
drivers/pci/Makefile
View file

@ -3,7 +3,8 @@
#
obj-y += access.o bus.o probe.o remove.o pci.o quirks.o slot.o \
pci-driver.o search.o pci-sysfs.o rom.o setup-res.o
pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
irq.o
obj-$(CONFIG_PROC_FS) += proc.o
# Build PCI Express stuff if needed

60
drivers/pci/irq.c Normal file
View file

@ -0,0 +1,60 @@
/*
* PCI IRQ failure handing code
*
* Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
*/
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/pci.h>
static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason)
{
struct pci_dev *parent = to_pci_dev(pdev->dev.parent);
dev_printk(KERN_ERR, &pdev->dev,
"Potentially misrouted IRQ (Bridge %s %04x:%04x)\n",
parent->dev.bus_id, parent->vendor, parent->device);
dev_printk(KERN_ERR, &pdev->dev, "%s\n", reason);
dev_printk(KERN_ERR, &pdev->dev, "Please report to linux-kernel@vger.kernel.org\n");
WARN_ON(1);
}
/**
* pci_lost_interrupt - reports a lost PCI interrupt
* @pdev: device whose interrupt is lost
*
* The primary function of this routine is to report a lost interrupt
* in a standard way which users can recognise (instead of blaming the
* driver).
*
* Returns:
* a suggestion for fixing it (although the driver is not required to
* act on this).
*/
enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev)
{
if (pdev->msi_enabled || pdev->msix_enabled) {
enum pci_lost_interrupt_reason ret;
if (pdev->msix_enabled) {
pci_note_irq_problem(pdev, "MSIX routing failure");
ret = PCI_LOST_IRQ_DISABLE_MSIX;
} else {
pci_note_irq_problem(pdev, "MSI routing failure");
ret = PCI_LOST_IRQ_DISABLE_MSI;
}
return ret;
}
#ifdef CONFIG_ACPI
if (!(acpi_disabled || acpi_noirq)) {
pci_note_irq_problem(pdev, "Potential ACPI misrouting please reboot with acpi=noirq");
/* currently no way to fix acpi on the fly */
return PCI_LOST_IRQ_DISABLE_ACPI;
}
#endif
pci_note_irq_problem(pdev, "unknown cause (not MSI or ACPI)");
return PCI_LOST_IRQ_NO_INFORMATION;
}
EXPORT_SYMBOL(pci_lost_interrupt);

7
include/linux/pci.h
View file

@ -546,6 +546,13 @@ struct pci_dev __deprecated *pci_find_slot(unsigned int bus,
unsigned int devfn);
#endif /* CONFIG_PCI_LEGACY */
enum pci_lost_interrupt_reason {
PCI_LOST_IRQ_NO_INFORMATION = 0,
PCI_LOST_IRQ_DISABLE_MSI,
PCI_LOST_IRQ_DISABLE_MSIX,
PCI_LOST_IRQ_DISABLE_ACPI,
};
enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *dev);
int pci_find_capability(struct pci_dev *dev, int cap);
int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap);
int pci_find_ext_capability(struct pci_dev *dev, int cap);