cpufreq: Make cpufreq_online() call driver->offline() on errors

In the CPU removal path the ->offline() callback provided by the
driver is always invoked before ->exit(), but in the cpufreq_online()
error path it is not, so ->exit() is expected to somehow know the
context in which it has been called and act accordingly.

That is less than straightforward, so make cpufreq_online() invoke
the driver's ->offline() callback, if present, on errors before
->exit() too.

This only potentially affects intel_pstate.

Fixes: 91a12e91dc39 ("cpufreq: Allow light-weight tear down and bring up of CPUs")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 802abc9..cbab834 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1367,9 +1367,14 @@ static int cpufreq_online(unsigned int cpu)
                        goto out_free_policy;
                }
 
+               /*
+                * The initialization has succeeded and the policy is online.
+                * If there is a problem with its frequency table, take it
+                * offline and drop it.
+                */
                ret = cpufreq_table_validate_and_sort(policy);
                if (ret)
-                       goto out_exit_policy;
+                       goto out_offline_policy;
 
                /* related_cpus should at least include policy->cpus. */
                cpumask_copy(policy->related_cpus, policy->cpus);
@@ -1515,6 +1520,10 @@ out_destroy_policy:
 
        up_write(&policy->rwsem);
 
+out_offline_policy:
+       if (cpufreq_driver->offline)
+               cpufreq_driver->offline(policy);
+
 out_exit_policy:
        if (cpufreq_driver->exit)
                cpufreq_driver->exit(policy);