1 files changed, 60 insertions, 7 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index ae11dd51f81d..aed2b0cb83dc 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1816,20 +1816,55 @@ EXPORT_SYMBOL(cpufreq_unregister_notifier);
  *                              GOVERNORS                            *
  *********************************************************************/
 
+/* Must set freqs->new to intermediate frequency */
+static int __target_intermediate(struct cpufreq_policy *policy,
+                                 struct cpufreq_freqs *freqs, int index)
+{
+        int ret;
+
+        freqs->new = cpufreq_driver->get_intermediate(policy, index);
+
+        /* We don't need to switch to intermediate freq */
+        if (!freqs->new)
+                return 0;
+
+        pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
+                 __func__, policy->cpu, freqs->old, freqs->new);
+
+        cpufreq_freq_transition_begin(policy, freqs);
+        ret = cpufreq_driver->target_intermediate(policy, index);
+        cpufreq_freq_transition_end(policy, freqs, ret);
+
+        if (ret)
+                pr_err("%s: Failed to change to intermediate frequency: %d\n",
+                       __func__, ret);
+
+        return ret;
+}
+
 static int __target_index(struct cpufreq_policy *policy,
                           struct cpufreq_frequency_table *freq_table, int index)
 {
-        struct cpufreq_freqs freqs;
+        struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
+        unsigned int intermediate_freq = 0;
         int retval = -EINVAL;
         bool notify;
 
         notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
-
         if (notify) {
-                freqs.old = policy->cur;
-                freqs.new = freq_table[index].frequency;
-                freqs.flags = 0;
+                /* Handle switching to intermediate frequency */
+                if (cpufreq_driver->get_intermediate) {
+                        retval = __target_intermediate(policy, &freqs, index);
+                        if (retval)
+                                return retval;
+
+                        intermediate_freq = freqs.new;
+                        /* Set old freq to intermediate */
+                        if (intermediate_freq)
+                                freqs.old = freqs.new;
+                }
 
+                freqs.new = freq_table[index].frequency;
                 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
                          __func__, policy->cpu, freqs.old, freqs.new);
 
@@ -1841,9 +1876,23 @@ static int __target_index(struct cpufreq_policy *policy,
                 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
                        retval);
 
-        if (notify)
+        if (notify) {
                 cpufreq_freq_transition_end(policy, &freqs, retval);
 
+                /*
+                 * Failed after setting to intermediate freq? Driver should have
+                 * reverted back to initial frequency and so should we. Check
+                 * here for intermediate_freq instead of get_intermediate, in
+                 * case we have't switched to intermediate freq at all.
+                 */
+                if (unlikely(retval && intermediate_freq)) {
+                        freqs.old = intermediate_freq;
+                        freqs.new = policy->restore_freq;
+                        cpufreq_freq_transition_begin(policy, &freqs);
+                        cpufreq_freq_transition_end(policy, &freqs, 0);
+                }
+        }
+
         return retval;
 }
 
@@ -1875,6 +1924,9 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
         if (target_freq == policy->cur)
                 return 0;
 
+        /* Save last value to restore later on errors */
+        policy->restore_freq = policy->cur;
+
         if (cpufreq_driver->target)
                 retval = cpufreq_driver->target(policy, target_freq, relation);
         else if (cpufreq_driver->target_index) {
@@ -2361,7 +2413,8 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
             !(driver_data->setpolicy || driver_data->target_index ||
                     driver_data->target) ||
              (driver_data->setpolicy && (driver_data->target_index ||
-                    driver_data->target)))
+                    driver_data->target)) ||
+             (!!driver_data->get_intermediate != !!driver_data->target_intermediate))
                 return -EINVAL;
 
         pr_debug("trying to register driver %s\n", driver_data->name);