[PATCH] cpufreq: amd-pstate: adjust min/max limit perf

[Meng Li]

The min/max limit perf values calculated based on frequency
may exceed the reasonable range of perf(highest perf, lowest perf).

Signed-off-by: Meng Li <li.m...@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index aa5e57e27d2b..2015c9fcc3c9 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -484,12 +484,19 @@ static int amd_pstate_verify(struct cpufreq_policy_data 
*policy)
 
 static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
 {
-       u32 max_limit_perf, min_limit_perf;
+       u32 max_limit_perf, min_limit_perf, lowest_perf;
        struct amd_cpudata *cpudata = policy->driver_data;
 
        max_limit_perf = div_u64(policy->max * cpudata->highest_perf, 
cpudata->max_freq);
        min_limit_perf = div_u64(policy->min * cpudata->highest_perf, 
cpudata->max_freq);
 
+       lowest_perf = READ_ONCE(cpudata->lowest_perf);
+       if (min_limit_perf < lowest_perf)
+               min_limit_perf = lowest_perf;
+
+       if (max_limit_perf < min_limit_perf)
+               max_limit_perf = min_limit_perf;
+
        WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
        WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
        WRITE_ONCE(cpudata->max_limit_freq, policy->max);
@@ -1387,6 +1394,12 @@ static void amd_pstate_epp_update_limit(struct 
cpufreq_policy *policy)
        max_limit_perf = div_u64(policy->max * cpudata->highest_perf, 
cpudata->max_freq);
        min_limit_perf = div_u64(policy->min * cpudata->highest_perf, 
cpudata->max_freq);
 
+       if (min_limit_perf < min_perf)
+               min_limit_perf = min_perf;
+
+       if (max_limit_perf < min_limit_perf)
+               max_limit_perf = min_limit_perf;
+
        WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
        WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
 
-- 
2.34.1