From: Pali Rohár <pali.rohar@gmail.com>
Date: Wed, 15 Oct 2014 23:16:51 +0000 (+0200)
Subject: cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy
X-Git-Tag: upstream/snapshot3+hdmi~1142
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e0d1e548952e7b1a0502ffd3ca6b17f4e831afdc;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy

commit 36b4bed5cd8f6e17019fa7d380e0836872c7b367 upstream.

Code which changes policy to powersave changes also max_policy_pct based on
max_freq. Code which change max_perf_pct has upper limit base on value
max_policy_pct. When policy is changing from powersave back to performance
then max_policy_pct is not changed. Which means that changing max_perf_pct is
not possible to high values if max_freq was too low in powersave policy.

Test case:

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
800000
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
3300000
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
100

$ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
$ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
powersave
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
800000
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
20

$ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
$ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
3300000
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
24

And now intel_pstate driver allows to set maximal value for max_perf_pct based
on max_policy_pct which is 24 for previous powersave max_freq 800000.

This patch will set default value for max_policy_pct when setting policy to
performance so it will allow to set also max value for max_perf_pct.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index ae52c77..cfd58b8 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -751,6 +751,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 	if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
 		limits.min_perf_pct = 100;
 		limits.min_perf = int_tofp(1);
+		limits.max_policy_pct = 100;
 		limits.max_perf_pct = 100;
 		limits.max_perf = int_tofp(1);
 		limits.no_turbo = limits.turbo_disabled;