| Message ID | CAKohpo=8oZKiq1ghuipitbfMp-bPxpWPQbGx5SLj9+_nGegCfA@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On Monday, June 24, 2013 06:38:17 PM Viresh Kumar wrote: > On 24 June 2013 17:13, Rafael J. Wysocki <rjw@sisk.pl> wrote: > > On Wednesday, June 19, 2013 02:23:07 PM Viresh Kumar wrote: > >> case CPUFREQ_POSTCHANGE: > >> + WARN_ON(!transition_ongoing--); > > > > Shouldn't we try to avoid going into the negative range here? > > What about this patch? Find it attached to apply. > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 2d53f47..6624694 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -107,6 +107,9 @@ static void handle_update(struct work_struct *work); > static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); > static struct srcu_notifier_head cpufreq_transition_notifier_list; > > +/* Tracks status of transition */ > +static int transition_ongoing; > + > static bool init_cpufreq_transition_notifier_list_called; > static int __init init_cpufreq_transition_notifier_list(void) > { > @@ -264,6 +267,13 @@ void __cpufreq_notify_transition(struct > cpufreq_policy *policy, > switch (state) { > > case CPUFREQ_PRECHANGE: > + if (transition_ongoing) { > + WARN(1, "In middle of another frequency transition\n"); > + return; > + } You can do if (WARN(transition_ongoing, "<text>")) return; and below analogously. > + > + transition_ongoing++; > + > /* detect if the driver reported a value as "old frequency" > * which is not equal to what the cpufreq core thinks is > * "old frequency". > @@ -283,6 +293,13 @@ void __cpufreq_notify_transition(struct > cpufreq_policy *policy, > break; > > case CPUFREQ_POSTCHANGE: > + if (!transition_ongoing) { > + WARN(1, "No frequency transition in progress\n"); > + return; > + } > + > + transition_ongoing--; > + > adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); > pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, > (unsigned long)freqs->cpu); > @@ -1458,6 +1475,8 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy, > > if (cpufreq_disabled()) > return -ENODEV; > + if (transition_ongoing) > + return -EBUSY; > > /* Make sure that target_freq is within supported range */ > if (target_freq > policy->max) Thanks, Rafael
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 2d53f47..6624694 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -107,6 +107,9 @@ static void handle_update(struct work_struct *work); static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); static struct srcu_notifier_head cpufreq_transition_notifier_list; +/* Tracks status of transition */ +static int transition_ongoing; + static bool init_cpufreq_transition_notifier_list_called; static int __init init_cpufreq_transition_notifier_list(void) { @@ -264,6 +267,13 @@ void __cpufreq_notify_transition(struct cpufreq_policy *policy, switch (state) { case CPUFREQ_PRECHANGE: + if (transition_ongoing) { + WARN(1, "In middle of another frequency transition\n"); + return; + } + + transition_ongoing++; + /* detect if the driver reported a value as "old frequency" * which is not equal to what the cpufreq core thinks is