| Message ID | 1416820083-20902-1-git-send-email-tomeu.vizoso@collabora.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On 24 November 2014 at 14:38, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote: > 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: Tomeu Vizoso <tomeu.vizoso@collabora.com> > > --- > > v2: * Properly unwind when erroring out. > --- > 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 4473eba..ae27ea6 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; > } We should add proper handling for error returned from sysfs_create_file() someday, but its obviously not what you are trying to fix. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tuesday, November 25, 2014 04:40:23 PM Viresh Kumar wrote: > On 24 November 2014 at 14:38, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote: > > 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: Tomeu Vizoso <tomeu.vizoso@collabora.com> > > > > --- > > > > v2: * Properly unwind when erroring out. > > --- > > 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 4473eba..ae27ea6 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; > > } > > We should add proper handling for error returned from sysfs_create_file() > someday, but its obviously not what you are trying to fix. > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Patch queued up for 3.19-rc1, thanks!
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 4473eba..ae27ea6 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 @@ err_get_freq: 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)
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: Tomeu Vizoso <tomeu.vizoso@collabora.com> --- v2: * Properly unwind when erroring out. --- drivers/cpufreq/cpufreq.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-)