[patch 02/19] ACPI: Prefer _CST over FADT for C-state capabilities

[Greg Kroah-Hartman <gregkh@suse.de>]

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-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>

[ACPI] Prefer _CST over FADT for C-state capabilities

Note: This ACPI standard compliance may cause regression
on some system, if they have _CST present, but _CST value
is bogus. "nocst" module parameter should workaround
that regression.

http://bugzilla.kernel.org/show_bug.cgi?id=5165

(cherry picked from 883baf7f7e81cca26f4683ae0d25ba48f094cc08 commit)

Signed-off-by: Venkatesh Pallipadi<venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/acpi/processor_idle.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- linux-2.6.14.4.orig/drivers/acpi/processor_idle.c
+++ linux-2.6.14.4/drivers/acpi/processor_idle.c
@@ -706,7 +706,7 @@ static int acpi_processor_get_power_info
 
 	/* Validate number of power states discovered */
 	if (pr->power.count < 2)
-		status = -ENODEV;
+		status = -EFAULT;
 
       end:
 	acpi_os_free(buffer.pointer);
@@ -857,11 +857,11 @@ static int acpi_processor_get_power_info
 	 * this function */
 
 	result = acpi_processor_get_power_info_cst(pr);
-	if ((result) || (acpi_processor_power_verify(pr) < 2)) {
+	if (result == -ENODEV)
 		result = acpi_processor_get_power_info_fadt(pr);
-		if ((result) || (acpi_processor_power_verify(pr) < 2))
-			result = acpi_processor_get_power_info_default_c1(pr);
-	}
+
+	if ((result) || (acpi_processor_power_verify(pr) < 2))
+		result = acpi_processor_get_power_info_default_c1(pr);
 
 	/*
 	 * Set Default Policy

--