[RFC Patch V2 07/16] x86, irq, ACPI: protect acpi_pci_irq_enable() from reentrance

Function acpi_pci_irq_enable() may be called twice for each PCI device present at boot time as below: 1) pci_acpi_init() --> acpi_pci_irq_enable() 2) pci_enable_device() --> pcibios_enable_device() --> acpi_pci_irq_enable() So protect acpi_pci_irq_enable() from

[RFC Patch V2 07/16] x86, irq, ACPI: protect acpi_pci_irq_enable() from reentrance

Function acpi_pci_irq_enable() may be called twice for each PCI device present at boot time as below: 1) pci_acpi_init() -- acpi_pci_irq_enable() 2) pci_enable_device() -- pcibios_enable_device() -- acpi_pci_irq_enable() So protect acpi_pci_irq_enable() from