Messages in this thread Patch in this message | | | Date | Sun, 21 Feb 2010 17:51:14 +0800 | Subject | Re: [2.6.33-rc5] Weird deadlock when shutting down | From | Américo Wang <> |
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On Sat, Feb 20, 2010 at 9:57 PM, Johannes Berg <johannes@sipsolutions.net> wrote: > On Sat, 2010-02-20 at 21:44 +0800, Américo Wang wrote: > >> That message is displayed before shutting down the devices. >> >> To verify, you can add some printk() in the end of >> __cpufreq_remove_dev(), or enable CONFIG_CPU_FREQ_DEBUG. > > That is already enabled. >
Ok, I got it.
Could you test the patch below? Thanks!
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Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 67bc2ec..e196084 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1113,6 +1113,8 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) unsigned int cpu = sys_dev->id; unsigned long flags; struct cpufreq_policy *data; + struct kobject *kobj; + struct completion *cmp; #ifdef CONFIG_SMP struct sys_device *cpu_sys_dev; unsigned int j; @@ -1141,10 +1143,11 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) dprintk("removing link\n"); cpumask_clear_cpu(cpu, data->cpus); spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - sysfs_remove_link(&sys_dev->kobj, "cpufreq"); + kobj = &sys_dev->kobj; cpufreq_cpu_put(data); cpufreq_debug_enable_ratelimit(); unlock_policy_rwsem_write(cpu); + sysfs_remove_link(kobj, "cpufreq"); return 0; } #endif @@ -1181,7 +1184,10 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) data->governor->name, CPUFREQ_NAME_LEN); #endif cpu_sys_dev = get_cpu_sysdev(j); - sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); + kobj = &cpu_sys_dev->kobj; + unlock_policy_rwsem_write(cpu); + sysfs_remove_link(kobj, "cpufreq"); + lock_policy_rwsem_write(cpu); cpufreq_cpu_put(data); } } @@ -1192,19 +1198,22 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) if (cpufreq_driver->target) __cpufreq_governor(data, CPUFREQ_GOV_STOP); - kobject_put(&data->kobj); + kobj = &data->kobj; + cmp = &data->kobj_unregister; + unlock_policy_rwsem_write(cpu); + kobject_put(kobj); /* we need to make sure that the underlying kobj is actually * not referenced anymore by anybody before we proceed with * unloading. */ dprintk("waiting for dropping of refcount\n"); - wait_for_completion(&data->kobj_unregister); + wait_for_completion(cmp); dprintk("wait complete\n"); + lock_policy_rwsem_write(cpu); if (cpufreq_driver->exit) cpufreq_driver->exit(data); - unlock_policy_rwsem_write(cpu); free_cpumask_var(data->related_cpus); | |