int pcibios_alloc_irq(struct pci_dev *dev)
{
+ /*
+ * If the PCI device was already claimed by core code and has
+ * MSI enabled, probing of the pcibios IRQ will overwrite
+ * dev->irq. So bail out if MSI is already enabled.
+ */
+ if (pci_dev_msi_enabled(dev))
+ return -EBUSY;
+
return pcibios_enable_irq(dev);
}