Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6d4e81ed authored by Tomeu Vizoso's avatar Tomeu Vizoso Committed by Rafael J. Wysocki
Browse files

cpufreq: Ref the policy object sooner 



Do it before it's assigned to cpufreq_cpu_data, otherwise when a driver
tries to get the cpu frequency during initialization the policy kobj is
referenced and we get this warning:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 64 at include/linux/kref.h:47 kobject_get+0x64/0x70()
Modules linked in:
CPU: 1 PID: 64 Comm: irq/77-tegra-ac Not tainted 3.18.0-rc4-next-20141114ccu-00050-g3eff942 #326
[<c0016fac>] (unwind_backtrace) from [<c001272c>] (show_stack+0x10/0x14)
[<c001272c>] (show_stack) from [<c06085d8>] (dump_stack+0x98/0xd8)
[<c06085d8>] (dump_stack) from [<c002892c>] (warn_slowpath_common+0x84/0xb4)
[<c002892c>] (warn_slowpath_common) from [<c00289f8>] (warn_slowpath_null+0x1c/0x24)
[<c00289f8>] (warn_slowpath_null) from [<c0220290>] (kobject_get+0x64/0x70)
[<c0220290>] (kobject_get) from [<c03e944c>] (cpufreq_cpu_get+0x88/0xc8)
[<c03e944c>] (cpufreq_cpu_get) from [<c03e9500>] (cpufreq_get+0xc/0x64)
[<c03e9500>] (cpufreq_get) from [<c0285288>] (actmon_thread_isr+0x134/0x198)
[<c0285288>] (actmon_thread_isr) from [<c0069008>] (irq_thread_fn+0x1c/0x40)
[<c0069008>] (irq_thread_fn) from [<c0069324>] (irq_thread+0x134/0x174)
[<c0069324>] (irq_thread) from [<c0040290>] (kthread+0xdc/0xf4)
[<c0040290>] (kthread) from [<c000f4b8>] (ret_from_fork+0x14/0x3c)
---[ end trace b7bd64a81b340c59 ]---

Signed-off-by: default avatarTomeu Vizoso <tomeu.vizoso@collabora.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent f41f4815

drivers/cpufreq/cpufreq.c

+21 −21
Original line number Diff line number Diff line
@@ -900,46 +900,31 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, 
	struct freq_attr **drv_attr;

	int ret = 0;



	/* prepare interface data */

	ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,

				   &dev->kobj, "cpufreq");

	if (ret)

		return ret;



	/* set up files for this cpu device */

	drv_attr = cpufreq_driver->attr;

	while ((drv_attr) && (*drv_attr)) {

		ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));

		if (ret)

			goto err_out_kobj_put;

			return ret;

		drv_attr++;

	}

	if (cpufreq_driver->get) {

		ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);

		if (ret)

			goto err_out_kobj_put;

			return ret;

	}



	ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);

	if (ret)

		goto err_out_kobj_put;

		return ret;



	if (cpufreq_driver->bios_limit) {

		ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);

		if (ret)

			goto err_out_kobj_put;

	}



	ret = cpufreq_add_dev_symlink(policy);

	if (ret)

		goto err_out_kobj_put;



			return ret;

	}



err_out_kobj_put:

	kobject_put(&policy->kobj);

	wait_for_completion(&policy->kobj_unregister);

	return ret;

	return cpufreq_add_dev_symlink(policy);

}



static void cpufreq_init_policy(struct cpufreq_policy *policy)
@@ -1198,6 +1183,8 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 
		goto err_set_policy_cpu;

	}



	down_write(&policy->rwsem);



	/* related cpus should atleast have policy->cpus */

	cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
@@ -1210,9 +1197,17 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 
	if (!recover_policy) {

		policy->user_policy.min = policy->min;

		policy->user_policy.max = policy->max;



		/* prepare interface data */

		ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,

					   &dev->kobj, "cpufreq");

		if (ret) {

			pr_err("%s: failed to init policy->kobj: %d\n",

			       __func__, ret);

			goto err_init_policy_kobj;

		}

	}



	down_write(&policy->rwsem);

	write_lock_irqsave(&cpufreq_driver_lock, flags);

	for_each_cpu(j, policy->cpus)

		per_cpu(cpufreq_cpu_data, j) = policy;
@@ -1303,6 +1298,11 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 
		per_cpu(cpufreq_cpu_data, j) = NULL;

	write_unlock_irqrestore(&cpufreq_driver_lock, flags);



	if (!recover_policy) {

		kobject_put(&policy->kobj);

		wait_for_completion(&policy->kobj_unregister);

	}

err_init_policy_kobj:

	up_write(&policy->rwsem);



	if (cpufreq_driver->exit)