[PATCH] x86/mrst/pci: avoid enabling intx for msi capable devices
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From: Jacob Pan on 21 Jun 2010 14:40 On Moorestown platform, true PCI devices with MSI capabilities do not support INTx mode. IRQ line# for those devices are zeros in the PCI shim, an attempt to enable INTx on these MSI capable devices will cause conflict in the system such as IRQ0 for the system timers. If the device driver probes/enables MSI before pci_enable_device(), the conflict is not shown since INTx will be disabled. But if the driver tries to enable INTx before MSI, the conflict will cause system timer IRQ0 to break. This patch will ensure the ordering of INTx and MSI setup by the driver is not relavent to INTx conflict. We will always skip INTx setup for MSI capable devices on Moorestown. Signed-off-by: Jacob Pan <jacob.jun.pan(a)linux.intel.com> --- arch/x86/pci/mrst.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/x86/pci/mrst.c b/arch/x86/pci/mrst.c index d5c7aef..ba3f08b 100644 --- a/arch/x86/pci/mrst.c +++ b/arch/x86/pci/mrst.c @@ -203,6 +203,9 @@ static int mrst_pci_irq_enable(struct pci_dev *dev) u8 pin; struct io_apic_irq_attr irq_attr; + if (pci_find_capability(dev, PCI_CAP_ID_MSI)) + return 0; + pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); /* MRST only have IOAPIC, the PCI irq lines are 1:1 mapped to -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |