--- arch/x86/include/asm/acpi.h
+++ arch/x86/include/asm/acpi.h
@@ -89,6 +89,7 @@ extern int acpi_ht;
extern int acpi_pci_disabled;
extern int acpi_skip_timer_override;
extern int acpi_use_timer_override;
+extern int acpi_fix_pin2_polarity;
extern u8 acpi_sci_flags;
extern int acpi_sci_override_gsi;