__cpufreq_add_dev() can fail sometimes while we are resuming our system.
Currently we are clearing all sysfs nodes for cpufreq's failed policy as that
could make userspace unstable. But if we suspend/resume again, we should atleast
try to bring back those policies.
This patch fixes this issue by clearing fallback data on failure and trying to
allocate a new struct cpufreq_policy on second resume.
Reported-and-tested-by: Bjørn Mork <bjorn(a)mork.no>
Signed-off-by: Viresh Kumar <viresh.kumar(a)linaro.org>
---
These are sent again (earlier sent as reply to emails), so that people can
give inputs if they have any.
Tested on my thinkpad T420.
drivers/cpufreq/cpufreq.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 16d7b4a..0a48e71 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1016,16 +1016,24 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
#endif
- if (frozen)
+ if (frozen) {
/* Restore the saved policy when doing light-weight init */
policy = cpufreq_policy_restore(cpu);
- else
+
+ /*
+ * As we failed to resume cpufreq core last time, lets try to
+ * create a new policy.
+ */
+ if (!policy)
+ frozen = false;
+ }
+
+ if (!frozen)
policy = cpufreq_policy_alloc();
if (!policy)
goto nomem_out;
-
/*
* In the resume path, since we restore a saved policy, the assignment
* to policy->cpu is like an update of the existing policy, rather than
@@ -1118,8 +1126,14 @@ err_get_freq:
if (cpufreq_driver->exit)
cpufreq_driver->exit(policy);
err_set_policy_cpu:
- if (frozen)
+ if (frozen) {
+ /*
+ * Clear fallback data as we should try to make things work on
+ * next suspend/resume
+ */
+ per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL;
cpufreq_policy_put_kobj(policy);
+ }
cpufreq_policy_free(policy);
nomem_out:
--
1.7.12.rc2.18.g61b472e
