| Message ID | 1416403291-7722-1-git-send-email-tomeu.vizoso@collabora.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
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 > -- 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
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)
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(-)