If the CONFIG_ACPI Kconfig symbol is not enabled and a partial build is attempted, compile errors will happen due missing types and identifiers. This can be easily reproduced with the following commands: $ export CROSS_COMPILE="arm-linux-gnueabihf-" ARCH=arm $ make allmodconfig $ make M=drivers/acpi/ CC drivers/acpi//tables.o drivers/acpi//tables.c:235:3: warning: 'struct acpi_subtable_proc' declared inside parameter list unsigned int max_entries) ^ drivers/acpi//tables.c:235:3: warning: its scope is only this definition or declaration, which is probably not what you want drivers/acpi//tables.c: In function 'acpi_parse_entries_array': drivers/acpi//tables.c:269:4: error: invalid use of undefined type 'struct acpi_subtable_proc' ... scripts/Makefile.build:258: recipe for target 'drivers/acpi//tables.o' failed make[1]: *** [drivers/acpi//tables.o] Error 1 Makefile:1401: recipe for target '_module_drivers/acpi/' failed make: *** [_module_drivers/acpi/] Error 2 This is because objects are tried to be built unconditionally even when CONFIG_ACPI is not enabled. This is usually not a problem since arches' Kconfig sources drivers/acpi/Kconfig directly and also selects ACPI but the Makefile should conditionally build the objects as well to prevent these build errors. Signed-off-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> --- Hello, I posted this patch first as an RFC more than a month ago [0] and got no feedback, so I'm resending without the RFC tag. [0]: https://lkml.org/lkml/2015/10/12/859 Best regards, Javier drivers/acpi/Makefile | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 675eaf337178..73ec23ca7db1 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -8,13 +8,13 @@ ccflags-$(CONFIG_ACPI_DEBUG) += -DACPI_DEBUG_OUTPUT # # ACPI Boot-Time Table Parsing # -obj-y += tables.o +obj-$(CONFIG_ACPI) += tables.o obj-$(CONFIG_X86) += blacklist.o # # ACPI Core Subsystem (Interpreter) # -obj-y += acpi.o \ +obj-$(CONFIG_ACPI) += acpi.o \ acpica/ # All the builtin files are in the "acpi." module_param namespace. @@ -66,10 +66,10 @@ obj-$(CONFIG_ACPI_FAN) += fan.o obj-$(CONFIG_ACPI_VIDEO) += video.o obj-$(CONFIG_ACPI_PCI_SLOT) += pci_slot.o obj-$(CONFIG_ACPI_PROCESSOR) += processor.o -obj-y += container.o +obj-$(CONFIG_ACPI) += container.o obj-$(CONFIG_ACPI_THERMAL) += thermal.o obj-$(CONFIG_ACPI_NFIT) += nfit.o -obj-y += acpi_memhotplug.o +obj-$(CONFIG_ACPI) += acpi_memhotplug.o obj-$(CONFIG_ACPI_HOTPLUG_IOAPIC) += ioapic.o obj-$(CONFIG_ACPI_BATTERY) += battery.o obj-$(CONFIG_ACPI_SBS) += sbshc.o -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
