On Sun, Aug 03, 2008 at 01:02:12PM -0500, James Bottomley wrote:
> 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.
James,
Can you add a paragraph to Documentation/pci.txt about the usage
of the new API?
thanks,
grant
>
> Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/pci/Makefile | 3 +-
> drivers/pci/irq.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/pci.h | 7 +++++
> 3 files changed, 69 insertions(+), 1 deletions(-)
> create mode 100644 drivers/pci/irq.c
>
> diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
> index 7d63f8c..19dacb8 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 0000000..6441dfa
> --- /dev/null
> +++ b/drivers/pci/irq.c
> @@ -0,0 +1,60 @@
> +/*
> + * PCI IRQ failure handing code
> + *
> + * Copyright (c) 2008 James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> + */
> +
> +#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@xxxxxxxxxxxxxxx\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 825be38..121698a 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -539,6 +539,13 @@ 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);
> --
> 1.5.6.3
>
>
>
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