Building the latest 2003 LTS can trigger following compilation error:
In file included from ./include/acpi/acpi_io.h:7:0, from ./include/linux/acpi.h:47, from ./arch/arm64/include/asm/machine_t.h:26, from arch/arm64/kernel/process.c:64: ./arch/arm64/include/asm/acpi.h:82:20: error: ‘enable_acpi’ redeclared as different kind of symbol static inline void enable_acpi(void) ^~~~~~~~~~~ In file included from arch/arm64/kernel/process.c:61:0: ./arch/arm64/include/asm/mpam_sched.h:46:2: note: previous definition of ‘enable_acpi’ was here enable_acpi,
The redefinition was introduced by commit 7e66740ad725 ("MPAM / ACPI: Refactoring MPAM init process and set MPAM ACPI as entrance")