intel_idle: allow idle states to be freeze-mode specific

Orabug: 24810432

intel_idle uses a NULL "enter" field in a cpuidle state
to recognize the invalid entry terminating a variable-length array.

Linux-4.0 added support for the system-wide "freeze" state
in cpuidle drivers via the new "enter_freeze" field.

The natural way to expose a deep idle state for freeze,
but not for run-time idle is to supply "enter_freeze" without "enter";
so we update the driver to accept such states.

Signed-off-by: Len Brown <len.brown@intel.com>
(cherry picked from commit 7dd0e0af64afe4aa08ccdd167f64bd007f09b515)
Signed-off-by: Brian Maly <brian.maly@oracle.com>

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 2a36a95d95cfa0ccba47924a69c00b3ce58de017..008e943d224dfaf39c73abf37110ef8a091e3921 100644 (file)
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -965,7 +965,8 @@ static int __init intel_idle_cpuidle_driver_init(void)
        for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
                int num_substates, mwait_hint, mwait_cstate;
 
-               if (cpuidle_state_table[cstate].enter == NULL)
+               if ((cpuidle_state_table[cstate].enter == NULL) &&
+                   (cpuidle_state_table[cstate].enter_freeze == NULL))
                        break;
 
                if (cstate + 1 > max_cstate) {