ACPI / init: Switch over platform to the ACPI mode later
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tue, 9 Jun 2015 23:33:36 +0000 (01:33 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 10 Jun 2015 21:51:27 +0000 (23:51 +0200)
commitb064a8fa77dfead647564c46ac8fc5b13bd1ab73
tree1785d715d4bb3671c44fa2c01341a89059286e94
parentd4a4f75cd8f29cd9464a5a32e9224a91571d6649
ACPI / init: Switch over platform to the ACPI mode later

Commit 73f7d1ca3263 "ACPI / init: Run acpi_early_init() before
timekeeping_init()" moved the ACPI subsystem initialization,
including the ACPI mode enabling, to an earlier point in the
initialization sequence, to allow the timekeeping subsystem
use ACPI early.  Unfortunately, that resulted in boot regressions
on some systems and the early ACPI initialization was moved toward
its original position in the kernel initialization code by commit
c4e1acbb35e4 "ACPI / init: Invoke early ACPI initialization later".

However, that turns out to be insufficient, as boot is still broken
on the Tyan S8812 mainboard.

To fix that issue, split the ACPI early initialization code into
two pieces so the majority of it still located in acpi_early_init()
and the part switching over the platform into the ACPI mode goes into
a new function, acpi_subsystem_init(), executed at the original early
ACPI initialization spot.

That fixes the Tyan S8812 boot problem, but still allows ACPI
tables to be loaded earlier which is useful to the EFI code in
efi_enter_virtual_mode().

Link: https://bugzilla.kernel.org/show_bug.cgi?id=97141
Fixes: 73f7d1ca3263 "ACPI / init: Run acpi_early_init() before timekeeping_init()"
Reported-and-tested-by: Marius Tolzmann <tolzmann@molgen.mpg.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Lee, Chun-Yi <jlee@suse.com>
drivers/acpi/bus.c
include/linux/acpi.h
init/main.c