* [PATCH] cpufreq: Ref the policy object sooner
@ 2015-03-09 4:20 Viresh Kumar
0 siblings, 0 replies; 3+ messages in thread
From: Viresh Kumar @ 2015-03-09 4:20 UTC (permalink / raw)
To: Rafael Wysocki, stable
Cc: linaro-kernel, linux-pm, santosh.shilimkar, ethan.zhao,
Tomeu Vizoso, Rafael J. Wysocki
From: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Upstream commit id: 6d4e81ed89c0
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 ]---
Cc: 3.18 <stable@vger.kernel.org> # 3.18
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/cpufreq/cpufreq.c | 42 +++++++++++++++++++++---------------------
1 file changed, 21 insertions(+), 21 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 4473eba1d6b0..ae27ea61799a 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -898,46 +898,31 @@ 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;
+ return ret;
}
- 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)
@@ -1196,6 +1181,8 @@ 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);
@@ -1208,9 +1195,17 @@ 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;
@@ -1301,6 +1296,11 @@ 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)
--
2.3.0.rc0.44.ga94655d
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH] cpufreq: Ref the policy object sooner
@ 2014-11-19 13:21 Tomeu Vizoso
2014-11-20 4:40 ` Viresh Kumar
0 siblings, 1 reply; 3+ messages in thread
From: Tomeu Vizoso @ 2014-11-19 13:21 UTC (permalink / raw)
To: linux-tegra
Cc: Javier Martinez Canillas, Tomeu Vizoso, Rafael J. Wysocki,
Viresh Kumar, linux-pm, linux-kernel
Do it before it's assigned to cpufreq_cpu_data, otherwise we can get
this warning when a driver tries to get the cpu frequency during
initialization:
------------[ 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: Tomeu Vizoso <tomeu.vizoso@collabora.com>
---
drivers/cpufreq/cpufreq.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 4473eba..954cb2f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -898,12 +898,6 @@ 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)) {
@@ -1211,6 +1205,15 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
}
down_write(&policy->rwsem);
+
+ /* 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;
+ }
+
write_lock_irqsave(&cpufreq_driver_lock, flags);
for_each_cpu(j, policy->cpus)
per_cpu(cpufreq_cpu_data, j) = policy;
@@ -1301,6 +1304,7 @@ err_get_freq:
per_cpu(cpufreq_cpu_data, j) = NULL;
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+err_init_policy_kobj:
up_write(&policy->rwsem);
if (cpufreq_driver->exit)
--
1.9.3
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] cpufreq: Ref the policy object sooner
2014-11-19 13:21 Tomeu Vizoso
@ 2014-11-20 4:40 ` Viresh Kumar
0 siblings, 0 replies; 3+ messages in thread
From: Viresh Kumar @ 2014-11-20 4:40 UTC (permalink / raw)
To: Tomeu Vizoso
Cc: linux-tegra@vger.kernel.org, Javier Martinez Canillas,
Rafael J. Wysocki, linux-pm@vger.kernel.org,
Linux Kernel Mailing List
On 19 November 2014 18:51, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote:
> Do it before it's assigned to cpufreq_cpu_data, otherwise we can get
> this warning when a driver tries to get the cpu frequency during
> initialization:
>
> ------------[ 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: Tomeu Vizoso <tomeu.vizoso@collabora.com>
> ---
> drivers/cpufreq/cpufreq.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 4473eba..954cb2f 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -898,12 +898,6 @@ 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)) {
> @@ -1211,6 +1205,15 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
> }
>
> down_write(&policy->rwsem);
> +
> + /* prepare interface data */
> + ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
> + &dev->kobj, "cpufreq");
This should be done only when (!recover_policy) and so you can merge
it with the 'if' block just above down_write. Actually you can move down_write()
a little bit up as well, just after ->init()
> + if (ret) {
> + pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
> + goto err_init_policy_kobj;
> + }
> +
> write_lock_irqsave(&cpufreq_driver_lock, flags);
> for_each_cpu(j, policy->cpus)
> per_cpu(cpufreq_cpu_data, j) = policy;
> @@ -1301,6 +1304,7 @@ err_get_freq:
> per_cpu(cpufreq_cpu_data, j) = NULL;
> write_unlock_irqrestore(&cpufreq_driver_lock, flags);
>
> +err_init_policy_kobj:
Oh, that's not enough and you need to get the relevant bits out from
the add_dev_interface() routine as well:
err_out_kobj_put:
kobject_put(&policy->kobj);
wait_for_completion(&policy->kobj_unregister);
> up_write(&policy->rwsem);
>
> if (cpufreq_driver->exit)
> --
> 1.9.3
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-03-09 4:20 [PATCH] cpufreq: Ref the policy object sooner Viresh Kumar
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2014-11-19 13:21 Tomeu Vizoso
2014-11-20 4:40 ` Viresh Kumar
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