Hi,

the bk-acpi.patch leads to following warning:

In file included from include/asm/fixmap.h:18,
                 from arch/i386/kernel/time_hpet.c:17:
include/asm/acpi.h: In function `__acpi_acquire_global_lock':
include/asm/acpi.h:72: Warnung: implicit declaration of function `cmpxchg'

The attached patch fixes it by including <asm/system.h>.

Best regards
  Thomas Schlichter