From 388c8c16abafc2e74dff173b5de9ee519ea8d32f Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Sun, 3 Aug 2008 13:02:12 -0500 Subject: [PATCH] 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 Signed-off-by: Jesse Barnes --- drivers/pci/Makefile | 3 ++- drivers/pci/irq.c | 60 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 7 ++++++ 3 files changed, 69 insertions(+), 1 deletion(-) create mode 100644 drivers/pci/irq.c diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index 4b47f4ece5b7..af3bfe22847b 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -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 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 @@ +/* + * PCI IRQ failure handing code + * + * Copyright (c) 2008 James Bottomley + */ + +#include +#include +#include +#include + +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); diff --git a/include/linux/pci.h b/include/linux/pci.h index 752def8a2ef4..c75b82bda327 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -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);