[PATCH] xen/cpufreq: Reset policy after enabling/disabling turbo status

[Jane Malalane <jane.malalane@xxxxxxxxxx>]

Before, user would change turbo status but this had no effect: boolean
was set but policy wasn't reevaluated.  Policy must be reevaluated so
that CPU frequency is chosen according to the turbo status and the
current governor.

Therefore, add __cpufreq_governor() in cpufreq_update_turbo().

Reported-by: <edvin.torok@xxxxxxxxxx>
Signed-off-by: <jane.malalane@xxxxxxxxxx>
---
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Ian Jackson <iwj@xxxxxxxxxxxxxx>
---

Release rationale:
Not taking this patch means that turbo status is misleading.

Taking this patch is low-risk as it only uses a function that already
exists and is already used for setting the chosen scaling governor.
Essentially, this change is equivalent to running 'xenpm
en/disable-turbo-mode' and, subsequently, running 'xenpm
set-scaling-governor <current governor>'.
---
 xen/drivers/cpufreq/utility.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/xen/drivers/cpufreq/utility.c b/xen/drivers/cpufreq/utility.c
index b93895d4dd..5f200ff3ee 100644
--- a/xen/drivers/cpufreq/utility.c
+++ b/xen/drivers/cpufreq/utility.c
@@ -417,10 +417,14 @@ int cpufreq_update_turbo(int cpuid, int new_state)
     {
         ret = cpufreq_driver.update(cpuid, policy);
         if (ret)
+        {
             policy->turbo = curr_state;
+            return ret;
+        }
     }
 
-    return ret;
+    /* Reevaluate current CPU policy. */
+    return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
 }
 
 
-- 
2.11.0