ACPI: processor: idle: Allow probing on platforms with one ACPI C-state

It is possible for ACPI _CST to return only one ACPI C-state, for
example, when deep cstate disabled in the BIOS.

And it is better for the acpi_idle driver to probe succesfully in
this case as well for consistency.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index dcc289e..75534c5 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -308,11 +308,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
        if (ret)
                return ret;
 
-       /*
-        * It is expected that there will be at least 2 states, C1 and
-        * something else (C2 or C3), so fail if that is not the case.
-        */
-       if (pr->power.count < 2)
+       if (!pr->power.count)
                return -EFAULT;
 
        pr->flags.has_cst = 1;
@@ -468,8 +464,7 @@ static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
                if (pr->power.states[i].valid) {
                        pr->power.count = i;
-                       if (pr->power.states[i].type >= ACPI_STATE_C2)
-                               pr->flags.power = 1;
+                       pr->flags.power = 1;
                }
        }