On Tuesday, December 24, 2013 07:11:00 AM Viresh Kumar wrote:
__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@mork.no Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
Well, while I appreciate the work done here, I don't like the changelog, I don't really like the way the code is written and I don't like the comments. Sorry about that.
Bjorn, can you please test the patch below instead along with the [2/2] from this series (on top of linux-pm.git/pm-cpufreq)?
Rafael
--- From: Rafael J. Wysocki rafael.j.wysocki@intel.com Subject: cpufreq: Clean up after a failing light-weight initialization
If cpufreq_policy_restore() returns NULL during system resume, __cpufreq_add_dev() should just fall back to the full initialization instead of returning an error, because that may actually make things work. Moreover, it should not leave stale fallback data behind after it has failed to restore a previously existing policy.
This change is based on Viresh Kumar's work.
Reported-by: Bjørn Mork bjorn@mork.no Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com --- drivers/cpufreq/cpufreq.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-)
Index: linux-pm/drivers/cpufreq/cpufreq.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq.c +++ linux-pm/drivers/cpufreq/cpufreq.c @@ -1016,15 +1016,17 @@ static int __cpufreq_add_dev(struct devi read_unlock_irqrestore(&cpufreq_driver_lock, flags); #endif
- if (frozen) - /* Restore the saved policy when doing light-weight init */ - policy = cpufreq_policy_restore(cpu); - else + /* + * Restore the saved policy when doing light-weight init and fall back + * to the full init if that fails. + */ + policy = frozen ? cpufreq_policy_restore(cpu) : NULL; + if (!policy) { + frozen = false; policy = cpufreq_policy_alloc(); - - if (!policy) - goto nomem_out; - + if (!policy) + goto nomem_out; + }
/* * In the resume path, since we restore a saved policy, the assignment @@ -1118,8 +1120,11 @@ err_get_freq: if (cpufreq_driver->exit) cpufreq_driver->exit(policy); err_set_policy_cpu: - if (frozen) + if (frozen) { + /* Do not leave stale fallback data behind. */ + per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; cpufreq_policy_put_kobj(policy); + } cpufreq_policy_free(policy);
nomem_out: