On Sunday, July 28, 2013 12:21:22 PM Toralf Förster wrote:
> On 07/28/2013 01:39 AM, Rafael J. Wysocki wrote:
> > On Saturday, July 27, 2013 07:40:34 PM Toralf Förster wrote:
> >> it gives at a ThinkPad T420:
> >>
> >> tfoerste@n22 ~/tmp $ lsmod | grep ^acpi_cpufreq
> >> acpi_cpufreq 12902 2147483647
> >
> > That is -1, which indicates some module refcount woes.
>
> yes, ofc.
>
> The issue apears after 1 s2ram/resume cycle, before s2ram the refcount is 1.
>
> > I definitely can't see that with the mainline on my machines.
>
> It is in mainline too.
Does the appended patch help?
Rafael
---
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Subject: cpufreq: Fix cpufreq driver module refcount balance after suspend/resume
Since cpufreq_cpu_put() called by __cpufreq_remove_dev() drops the
driver module refcount, the latter has to bump up that refcount to
start with to balance the drop, or the cpufreq driver refcount will
become negative after a suspend/resume cycle.
Reported-by: Toralf Förster <toralf.foerster@xxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
Index: linux-pm/drivers/cpufreq/cpufreq.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq.c
+++ linux-pm/drivers/cpufreq/cpufreq.c
@@ -1016,6 +1016,9 @@ static int __cpufreq_remove_dev(struct d
pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
+ if (!try_module_get(cpufreq_driver->owner))
+ return -EINVAL;
+
write_lock_irqsave(&cpufreq_driver_lock, flags);
data = per_cpu(cpufreq_cpu_data, cpu);
@@ -1025,7 +1028,8 @@ static int __cpufreq_remove_dev(struct d
if (!data) {
pr_debug("%s: No cpu_data found\n", __func__);
- return -EINVAL;
+ ret = -EINVAL;
+ goto err;
}
if (cpufreq_driver->target)
@@ -1063,9 +1067,9 @@ static int __cpufreq_remove_dev(struct d
unlock_policy_rwsem_write(cpu);
- ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj,
+ sysfs_create_link(&cpu_dev->kobj, &data->kobj,
"cpufreq");
- return -EINVAL;
+ goto err;
}
WARN_ON(lock_policy_rwsem_write(cpu));
@@ -1110,6 +1114,10 @@ static int __cpufreq_remove_dev(struct d
per_cpu(cpufreq_policy_cpu, cpu) = -1;
return 0;
+
+ err:
+ module_put(cpufreq_driver->owner);
+ return ret;
}
--
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