[v2,6/6] ACPI: in HW reduced mode, using FADT PM information is not allowed.

Message ID 1385080915-23430-7-git-send-email-al.stone@linaro.org
State New
Headers show

Commit Message

Al Stone Nov. 22, 2013, 12:41 a.m.
From: Al Stone <al.stone@linaro.org>

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 <al.stone@linaro.og>
---
 drivers/acpi/processor_idle.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Patch

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index b18e7ab..52859da 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -272,6 +272,14 @@  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;