intel_pstate: Fix user input of min/max to legal policy region
In current code, max_perf_pct might be smaller than min_perf_pct
by improper user input:
$ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct
/sys/devices/system/cpu/intel_pstate/max_perf_pct:100
/sys/devices/system/cpu/intel_pstate/min_perf_pct:100
$ echo 80 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
$ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct
/sys/devices/system/cpu/intel_pstate/max_perf_pct:80
/sys/devices/system/cpu/intel_pstate/min_perf_pct:100
Fix this problem by 2 steps:
1. Normalize the user input to [min_policy, max_policy].
2. Make sure max_perf_pct>=min_perf_pct, suggested by Seiichi Ikarashi.
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 31d0548..63075cc 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -423,6 +423,8 @@
limits.max_sysfs_pct = clamp_t(int, input, 0 , 100);
limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
+ limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct);
+ limits.max_perf_pct = max(limits.min_perf_pct, limits.max_perf_pct);
limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
if (hwp_active)
@@ -442,6 +444,8 @@
limits.min_sysfs_pct = clamp_t(int, input, 0 , 100);
limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
+ limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct);
+ limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
if (hwp_active)
@@ -989,12 +993,19 @@
limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100);
- limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
- limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
-
limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq;
limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100);
+
+ /* Normalize user input to [min_policy_pct, max_policy_pct] */
+ limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
+ limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct);
limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
+ limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct);
+
+ /* Make sure min_perf_pct <= max_perf_pct */
+ limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
+
+ limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
if (hwp_active)