From: Al Stone <redacted>
Per the ACPI 5.0 specification, section 5.2.9, none of the power
management fields in the FADT are to be used. Short-circuit using
any of those fields in acpi_processor_get_power_info_fadt().
Signed-off-by: Al Stone <redacted>
---
drivers/acpi/processor_idle.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 8b48c08..a419fcb 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -271,6 +271,14 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
if (!pr->pblk)
return -ENODEV;
+ /*
+ * Using power management information from the FADT is not
+ * allowed when in HW reduced mode. See ACPI 5.0, section
+ * 5.2.9.
+ */
+ if (acpi_gbl_reduced_hardware)
+ return -ENODEV;
+
/* if info is obtained from pblk/fadt, type equals state */
pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
--
1.8.3.1