ACPI / init: Invoke early ACPI initialization later
Commit 73f7d1ca3263 (ACPI / init: Run acpi_early_init() before
timekeeping_init()) optimistically moved the early ACPI initialization
before timekeeping_init(), but that didn't work, because it broke fast
TSC calibration for Julian Wollrath on Thinkpad x121e (and most likely
for others too). The reason is that acpi_early_init() enables the SCI
and that interferes with the fast TSC calibration mechanism.
Thus follow the original idea to execute acpi_early_init() before
efi_enter_virtual_mode() to help the EFI people for now and we can
revisit the other problem that commit 73f7d1ca3263 attempted to
address in the future (if really necessary).
Fixes: 73f7d1ca3263 (ACPI / init: Run acpi_early_init() before timekeeping_init())
Reported-by: Julian Wollrath <jwollrath@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/init/main.c b/init/main.c
index eb03090..9c7fd4c 100644
--- a/init/main.c
+++ b/init/main.c
@@ -561,7 +561,6 @@
init_timers();
hrtimers_init();
softirq_init();
- acpi_early_init();
timekeeping_init();
time_init();
sched_clock_postinit();
@@ -613,6 +612,7 @@
calibrate_delay();
pidmap_init();
anon_vma_init();
+ acpi_early_init();
#ifdef CONFIG_X86
if (efi_enabled(EFI_RUNTIME_SERVICES))
efi_enter_virtual_mode();