On Mon, Dec 27, 2021 at 6:43 PM Niklas Schnelle <schnelle@xxxxxxxxxxxxx> wrote: > > On Mon, 2021-12-27 at 18:15 +0100, Rafael J. Wysocki wrote: > > On Mon, Dec 27, 2021 at 6:12 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > > > On Mon, Dec 27, 2021 at 6:02 PM Niklas Schnelle <schnelle@xxxxxxxxxxxxx> wrote: > > > > On Mon, 2021-12-27 at 17:47 +0100, Rafael J. Wysocki wrote: > > > > > On Mon, Dec 27, 2021 at 5:44 PM Niklas Schnelle <schnelle@xxxxxxxxxxxxx> wrote: > > > > > > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends > > > > > > not being declared. As ACPI always uses I/O port access > > > > > > > > > > The ARM64 people may not agree with this. > > > > > > > > Maybe my wording is bad. This is my rewording of what Arnd had in his > > > > original mail: "The ACPI subsystem needs access to I/O ports, so that > > > > also gets a dependency."( > > > > https://lore.kernel.org/lkml/CAK8P3a0MNbx-iuzW_-=0ab6-TTZzwV-PT_6gAC1Gp5PgYyHcrA@xxxxxxxxxxxxxx/ > > > > ). > > > > > > And my point is that on ARM64 the ACPI subsystem does not need to > > > access IO ports. > > > > > > It may not even need to access them on x86, but that depends on the > > > platform firmware in use. > > Well at least it does compile code calling outb() in > drivers/acpi/ec.c:acpi_ec_write_cmd(). That's the EC driver which is not used on arm64 AFAICS and that driver itself can be made depend on HAS_IOPORT. > Not sure if there is an > alternative path at runtime if there is then we might want to instead > use ifdefs to always use the non I/O port path if HAS_IOPORT is > undefined. > > > > > > > If arm64 is going to set HAS_IOPORT, then fine, but is it (and this > > > applies to ia64 too)? > > Yes x86, arm64 and ia64 that is all arches that set ACH_SUPPORTS_ACPI > all select HAS_IOPORT too. See patch 02 or the summary in the cover > letter which notes that only s390, nds32, um, h8300, nios2, openrisc, > hexagon, csky, and xtensa do not select it. If that is the case, there should be no need to add the extra dependency to CONFIG_ACPI. > > > > > > > > > we depend on HAS_IOPORT unconditionally. > > > > > > > > > > > > Co-developed-by: Arnd Bergmann <arnd@xxxxxxxxxx> > > > > > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxxxx> > > > > > > Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> > > > > > > --- > > > > > > drivers/acpi/Kconfig | 1 + > > > > > > 1 file changed, 1 insertion(+) > > > > > > > > > > > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > > > > > > index cdbdf68bd98f..b57f15817ede 100644 > > > > > > --- a/drivers/acpi/Kconfig > > > > > > +++ b/drivers/acpi/Kconfig > > > > > > @@ -9,6 +9,7 @@ config ARCH_SUPPORTS_ACPI > > > > > > menuconfig ACPI > > > > > > bool "ACPI (Advanced Configuration and Power Interface) Support" > > > > > > depends on ARCH_SUPPORTS_ACPI > > > > Besides, I'm not sure why ARCH_SUPPORTS_ACPI cannot cover this new dependency. > > If you prefer to have the dependency there that should work too yes. I would prefer that. IMO, if ARCH_SUPPORTS_ACPI is set, all of the requisite dependencies should be met.
