On 15 April 2013 21:37, Dirk Brandewie wrote: > If the intel_pstate driver is being used __cpufreq_governor() should NOT be > called intel_pstate does not implement the target() callback. > > Nathan's commit 5800043b2 changed the fence around the call to > __cpufreq_governor() in __cpufreq_remove_dev() here is the relevant hunk. No it isn't. > + if (has_target) > __cpufreq_governor(data, CPUFREQ_GOV_STOP); As it has taken care of this limitation. BUT some of my earlier patches haven't. :( Here is the fix (Sedat please try this and give your tested-by, use the attached patch as gmail might break what i am copying in mail).. Sorry for being late in fixing this issue, i am still down with Tonsil infection and fever.. Today only i got some power to fix it after seeing Dirk's mail. Your tested-by may help me to recover quickly :) @Rafael: I will probably be down for one more week and so not doing any reviews for now... I do check important mails sent directly to me though. ------------x----------------------x------------------ From: Viresh Kumar Date: Mon, 15 Apr 2013 22:43:57 +0530 Subject: [PATCH] cpufreq: Don't call __cpufreq_governor() for drivers without target() Some cpufreq drivers implement their own governor and so don't need us to call generic governors interface via __cpufreq_governor(). Few recent commits haven't obeyed this law well and we saw some regressions. This patch tries to fix this issue. Signed-off-by: Viresh Kumar --- drivers/cpufreq/cpufreq.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 3564947..a6f6595 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -858,13 +858,18 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, struct device *dev) { struct cpufreq_policy *policy; - int ret = 0; + int ret = 0, has_target = 0; unsigned long flags; policy = cpufreq_cpu_get(sibling); WARN_ON(!policy); - __cpufreq_governor(policy, CPUFREQ_GOV_STOP); + rcu_read_lock(); + has_target = !!rcu_dereference(cpufreq_driver)->target; + rcu_read_unlock(); + + if (has_target) + __cpufreq_governor(policy, CPUFREQ_GOV_STOP); lock_policy_rwsem_write(sibling); @@ -877,8 +882,10 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, unlock_policy_rwsem_write(sibling); - __cpufreq_governor(policy, CPUFREQ_GOV_START); - __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); + if (has_target) { + __cpufreq_governor(policy, CPUFREQ_GOV_START); + __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); + } ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); if (ret) { @@ -1146,7 +1153,8 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif /* If cpu is last user of policy, free policy */ if (cpus == 1) { - __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); + if (has_target) + __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); lock_policy_rwsem_read(cpu); kobj = &data->kobj;