Commits
Jiang Liu committed cffe0a2b5a3
x86, irq: Keep balance of IOAPIC pin reference count To keep balance of IOAPIC pin reference count, we need to protect pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable() from reentrance. There are two cases which will cause reentrance. The first case is caused by suspend/hibernation. If pcibios_disable_irq is called during suspending/hibernating, we don't release the assigned IRQ number, otherwise it may break the suspend/hibernation. So late when pcibios_enable_irq is called during resume, we shouldn't allocate IRQ number again. The second case is that function acpi_pci_irq_enable() may be called twice for PCI devices present at boot time as below: 1) pci_acpi_init() --> acpi_pci_irq_enable() if pci_routeirq is true 2) pci_enable_device() --> pcibios_enable_device() --> acpi_pci_irq_enable() We can't kill kernel parameter pci_routeirq yet because it's still needed for debugging purpose. So flag irq_managed is introduced to track whether IRQ number is assigned by OS and to protect pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable() from reentrance. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Len Brown <lenb@kernel.org> Link: http://lkml.kernel.org/r/1414387308-27148-13-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>