| Message ID | 1443607098-26666-2-git-send-email-tomeu.vizoso@collabora.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On 30 September 2015 at 11:58, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote: > If a suitable prepare callback cannot be found for a given device and > its driver has no PM callbacks at all, assume that it can go direct to > complete when the system goes to sleep. > > The reason for this is that there's lots of devices in a system that do > no PM at all and there's no reason for them to prevent their ancestors > to do direct_complete if they can support it. > > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> > --- > > Changes in v7: > - Reduce indentation by adding a label in device_prepare() > > Changes in v6: > - Add stub for !CONFIG_PM. > - Move implementation of device_check_pm_callbacks to power/main.c as it > doesn't belong to CONFIG_PM_SLEEP. > - Take dev->power.lock before modifying flag. > > Changes in v5: > - Check for all dev_pm_ops instances associated to a device, updating a > no_pm_callbacks flag at the times when that could change. > > drivers/base/dd.c | 3 +++ > drivers/base/power/common.c | 27 +++++++++++++++++++++++++++ > drivers/base/power/domain.c | 5 +++++ > drivers/base/power/main.c | 8 ++++++++ > drivers/base/power/power.h | 6 ++++++ > include/linux/pm.h | 1 + > 6 files changed, 50 insertions(+) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index be0eb4639128..fe0e9cb684b8 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -205,6 +205,8 @@ static void driver_bound(struct device *dev) > > klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); > > + device_check_pm_callbacks(dev); > + > /* > * Make sure the device is no longer in one of the deferred lists and > * kick off retrying all pending devices > @@ -695,6 +697,7 @@ static void __device_release_driver(struct device *dev) > dev->pm_domain->dismiss(dev); > > klist_remove(&dev->p->knode_driver); > + device_check_pm_callbacks(dev); > if (dev->bus) > blocking_notifier_call_chain(&dev->bus->p->bus_notifier, > BUS_NOTIFY_UNBOUND_DRIVER, > diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c > index f32b802b98f4..1bba85f8bf8a 100644 > --- a/drivers/base/power/common.c > +++ b/drivers/base/power/common.c > @@ -128,3 +128,30 @@ void dev_pm_domain_detach(struct device *dev, bool power_off) > dev->pm_domain->detach(dev, power_off); > } > EXPORT_SYMBOL_GPL(dev_pm_domain_detach); > + > +static bool pm_ops_is_empty(const struct dev_pm_ops *ops) > +{ > + if (!ops) > + return true; > + > + return !ops->prepare && > + !ops->suspend && > + !ops->suspend_late && > + !ops->suspend_noirq && > + !ops->resume_noirq && > + !ops->resume_early && > + !ops->resume && > + !ops->complete; > +} > + > +void device_check_pm_callbacks(struct device *dev) > +{ > + spin_lock_irq(&dev->power.lock); > + dev->power.no_pm_callbacks = > + (!dev->bus || pm_ops_is_empty(dev->bus->pm)) && > + (!dev->class || pm_ops_is_empty(dev->class->pm)) && > + (!dev->type || pm_ops_is_empty(dev->type->pm)) && > + (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) && > + (!dev->driver || pm_ops_is_empty(dev->driver->pm)); > + spin_unlock_irq(&dev->power.lock); > +} > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 16550c63d611..3cae1aa1885b 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -20,6 +20,8 @@ > #include <linux/suspend.h> > #include <linux/export.h> > > +#include "power.h" > + > #define GENPD_RETRY_MAX_MS 250 /* Approximate */ > > #define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \ > @@ -1305,6 +1307,7 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, > > list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); > > + device_check_pm_callbacks(dev); Don't do this while the genpd mutex is held as there is no need to. Please move it outside the lock and only do it for non-error case. > out: > mutex_unlock(&genpd->lock); > > @@ -1369,6 +1372,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, > > genpd_free_dev_data(dev, gpd_data); > > + device_check_pm_callbacks(dev); > + > return 0; I can't tell whether this is an interesting feature to use for devices that gets attached to the ACPI PM domain. Although, you currently doesn't deal with that case, and too me I think this looks a bit weird/unsymmetrical. > > out: > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > index 1710c26ba097..5af45d20b677 100644 > --- a/drivers/base/power/main.c > +++ b/drivers/base/power/main.c > @@ -131,6 +131,8 @@ void device_pm_add(struct device *dev) > dev_name(dev->parent)); > list_add_tail(&dev->power.entry, &dpm_list); > mutex_unlock(&dpm_list_mtx); > + > + device_check_pm_callbacks(dev); > } > > /** > @@ -1569,6 +1571,11 @@ static int device_prepare(struct device *dev, pm_message_t state) > > dev->power.wakeup_path = device_may_wakeup(dev); > > + if (dev->power.no_pm_callbacks) { > + ret = 1; /* Let device go direct_complete */ > + goto unlock; > + } > + > if (dev->pm_domain) { > info = "preparing power domain "; > callback = dev->pm_domain->ops.prepare; > @@ -1591,6 +1598,7 @@ static int device_prepare(struct device *dev, pm_message_t state) > if (callback) > ret = callback(dev); > > +unlock: > device_unlock(dev); > > if (ret < 0) { > diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h > index 998fa6b23084..f665a7850016 100644 > --- a/drivers/base/power/power.h > +++ b/drivers/base/power/power.h > @@ -29,6 +29,8 @@ struct wake_irq { > extern void dev_pm_arm_wake_irq(struct wake_irq *wirq); > extern void dev_pm_disarm_wake_irq(struct wake_irq *wirq); > > +extern void device_check_pm_callbacks(struct device *dev); > + > #ifdef CONFIG_PM_SLEEP > > extern int device_wakeup_attach_irq(struct device *dev, > @@ -102,6 +104,10 @@ static inline void dev_pm_disarm_wake_irq(struct wake_irq *wirq) > { > } > > +static inline void device_check_pm_callbacks(struct device *dev) > +{ > +} > + > #endif > > #ifdef CONFIG_PM_SLEEP > diff --git a/include/linux/pm.h b/include/linux/pm.h > index 35d599e7250d..e334b9b8cd46 100644 > --- a/include/linux/pm.h > +++ b/include/linux/pm.h > @@ -566,6 +566,7 @@ struct dev_pm_info { > bool ignore_children:1; > bool early_init:1; /* Owned by the PM core */ > bool direct_complete:1; /* Owned by the PM core */ > + bool no_pm_callbacks:1; /* Owned by the PM core */ This flag is only being used while CONFIG_PM is set. I suggest we move within that ifdef. > spinlock_t lock; > #ifdef CONFIG_PM_SLEEP > struct list_head entry; > -- > 2.4.3 > Kind regards Uffe -- 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 Wednesday, September 30, 2015 01:33:29 PM Ulf Hansson wrote: > On 30 September 2015 at 11:58, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote: > > If a suitable prepare callback cannot be found for a given device and > > its driver has no PM callbacks at all, assume that it can go direct to > > complete when the system goes to sleep. > > > > The reason for this is that there's lots of devices in a system that do > > no PM at all and there's no reason for them to prevent their ancestors > > to do direct_complete if they can support it. > > > > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> > > --- > > > > Changes in v7: > > - Reduce indentation by adding a label in device_prepare() > > > > Changes in v6: > > - Add stub for !CONFIG_PM. > > - Move implementation of device_check_pm_callbacks to power/main.c as it > > doesn't belong to CONFIG_PM_SLEEP. > > - Take dev->power.lock before modifying flag. > > > > Changes in v5: > > - Check for all dev_pm_ops instances associated to a device, updating a > > no_pm_callbacks flag at the times when that could change. > > > > drivers/base/dd.c | 3 +++ > > drivers/base/power/common.c | 27 +++++++++++++++++++++++++++ > > drivers/base/power/domain.c | 5 +++++ > > drivers/base/power/main.c | 8 ++++++++ > > drivers/base/power/power.h | 6 ++++++ > > include/linux/pm.h | 1 + > > 6 files changed, 50 insertions(+) > > > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > > index be0eb4639128..fe0e9cb684b8 100644 > > --- a/drivers/base/dd.c > > +++ b/drivers/base/dd.c > > @@ -205,6 +205,8 @@ static void driver_bound(struct device *dev) > > > > klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); > > > > + device_check_pm_callbacks(dev); > > + > > /* > > * Make sure the device is no longer in one of the deferred lists and > > * kick off retrying all pending devices > > @@ -695,6 +697,7 @@ static void __device_release_driver(struct device *dev) > > dev->pm_domain->dismiss(dev); > > > > klist_remove(&dev->p->knode_driver); > > + device_check_pm_callbacks(dev); > > if (dev->bus) > > blocking_notifier_call_chain(&dev->bus->p->bus_notifier, > > BUS_NOTIFY_UNBOUND_DRIVER, > > diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c > > index f32b802b98f4..1bba85f8bf8a 100644 > > --- a/drivers/base/power/common.c > > +++ b/drivers/base/power/common.c > > @@ -128,3 +128,30 @@ void dev_pm_domain_detach(struct device *dev, bool power_off) > > dev->pm_domain->detach(dev, power_off); > > } > > EXPORT_SYMBOL_GPL(dev_pm_domain_detach); > > + > > +static bool pm_ops_is_empty(const struct dev_pm_ops *ops) > > +{ > > + if (!ops) > > + return true; > > + > > + return !ops->prepare && > > + !ops->suspend && > > + !ops->suspend_late && > > + !ops->suspend_noirq && > > + !ops->resume_noirq && > > + !ops->resume_early && > > + !ops->resume && > > + !ops->complete; > > +} > > + > > +void device_check_pm_callbacks(struct device *dev) > > +{ > > + spin_lock_irq(&dev->power.lock); > > + dev->power.no_pm_callbacks = > > + (!dev->bus || pm_ops_is_empty(dev->bus->pm)) && > > + (!dev->class || pm_ops_is_empty(dev->class->pm)) && > > + (!dev->type || pm_ops_is_empty(dev->type->pm)) && > > + (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) && > > + (!dev->driver || pm_ops_is_empty(dev->driver->pm)); > > + spin_unlock_irq(&dev->power.lock); > > +} > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > > index 16550c63d611..3cae1aa1885b 100644 > > --- a/drivers/base/power/domain.c > > +++ b/drivers/base/power/domain.c > > @@ -20,6 +20,8 @@ > > #include <linux/suspend.h> > > #include <linux/export.h> > > > > +#include "power.h" > > + > > #define GENPD_RETRY_MAX_MS 250 /* Approximate */ > > > > #define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \ > > @@ -1305,6 +1307,7 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, > > > > list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); > > > > + device_check_pm_callbacks(dev); > > Don't do this while the genpd mutex is held as there is no need to. > Please move it outside the lock and only do it for non-error case. > > > out: > > mutex_unlock(&genpd->lock); > > > > @@ -1369,6 +1372,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, > > > > genpd_free_dev_data(dev, gpd_data); > > > > + device_check_pm_callbacks(dev); > > + > > return 0; > > I can't tell whether this is an interesting feature to use for devices > that gets attached to the ACPI PM domain. Although, you currently > doesn't deal with that case, and too me I think this looks a bit > weird/unsymmetrical. Good point. It needs to be done in every situation where a PM domain is or can be used. I guess we might require all PM domains to be attached to devices after a successful probe at the latest (no PM domains should be attached/detached after probe succeeds IOW), in which case it should be sufficient to do the device_check_pm_callbacks() thing each time after probe successds. Thoughts? > > out: > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > > index 1710c26ba097..5af45d20b677 100644 > > --- a/drivers/base/power/main.c > > +++ b/drivers/base/power/main.c > > @@ -131,6 +131,8 @@ void device_pm_add(struct device *dev) > > dev_name(dev->parent)); > > list_add_tail(&dev->power.entry, &dpm_list); > > mutex_unlock(&dpm_list_mtx); > > + > > + device_check_pm_callbacks(dev); > > } > > > > /** > > @@ -1569,6 +1571,11 @@ static int device_prepare(struct device *dev, pm_message_t state) > > > > dev->power.wakeup_path = device_may_wakeup(dev); > > > > + if (dev->power.no_pm_callbacks) { > > + ret = 1; /* Let device go direct_complete */ > > + goto unlock; > > + } > > + > > if (dev->pm_domain) { > > info = "preparing power domain "; > > callback = dev->pm_domain->ops.prepare; > > @@ -1591,6 +1598,7 @@ static int device_prepare(struct device *dev, pm_message_t state) > > if (callback) > > ret = callback(dev); > > > > +unlock: > > device_unlock(dev); > > > > if (ret < 0) { > > diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h > > index 998fa6b23084..f665a7850016 100644 > > --- a/drivers/base/power/power.h > > +++ b/drivers/base/power/power.h > > @@ -29,6 +29,8 @@ struct wake_irq { > > extern void dev_pm_arm_wake_irq(struct wake_irq *wirq); > > extern void dev_pm_disarm_wake_irq(struct wake_irq *wirq); > > > > +extern void device_check_pm_callbacks(struct device *dev); > > + > > #ifdef CONFIG_PM_SLEEP > > > > extern int device_wakeup_attach_irq(struct device *dev, > > @@ -102,6 +104,10 @@ static inline void dev_pm_disarm_wake_irq(struct wake_irq *wirq) > > { > > } > > > > +static inline void device_check_pm_callbacks(struct device *dev) > > +{ > > +} > > + > > #endif > > > > #ifdef CONFIG_PM_SLEEP > > diff --git a/include/linux/pm.h b/include/linux/pm.h > > index 35d599e7250d..e334b9b8cd46 100644 > > --- a/include/linux/pm.h > > +++ b/include/linux/pm.h > > @@ -566,6 +566,7 @@ struct dev_pm_info { > > bool ignore_children:1; > > bool early_init:1; /* Owned by the PM core */ > > bool direct_complete:1; /* Owned by the PM core */ > > + bool no_pm_callbacks:1; /* Owned by the PM core */ > > This flag is only being used while CONFIG_PM is set. I suggest we move > within that ifdef. I guess you mean CONFIG_PM_SLEEP? > > spinlock_t lock; > > #ifdef CONFIG_PM_SLEEP > > struct list_head entry; Thanks, Rafael -- 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/base/power/domain.c b/drivers/base/power/domain.c >> > index 16550c63d611..3cae1aa1885b 100644 >> > --- a/drivers/base/power/domain.c >> > +++ b/drivers/base/power/domain.c >> > @@ -20,6 +20,8 @@ >> > #include <linux/suspend.h> >> > #include <linux/export.h> >> > >> > +#include "power.h" >> > + >> > #define GENPD_RETRY_MAX_MS 250 /* Approximate */ >> > >> > #define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \ >> > @@ -1305,6 +1307,7 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, >> > >> > list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); >> > >> > + device_check_pm_callbacks(dev); >> >> Don't do this while the genpd mutex is held as there is no need to. >> Please move it outside the lock and only do it for non-error case. >> >> > out: >> > mutex_unlock(&genpd->lock); >> > >> > @@ -1369,6 +1372,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, >> > >> > genpd_free_dev_data(dev, gpd_data); >> > >> > + device_check_pm_callbacks(dev); >> > + >> > return 0; >> >> I can't tell whether this is an interesting feature to use for devices >> that gets attached to the ACPI PM domain. Although, you currently >> doesn't deal with that case, and too me I think this looks a bit >> weird/unsymmetrical. > > Good point. > > It needs to be done in every situation where a PM domain is or can be used. > > I guess we might require all PM domains to be attached to devices after > a successful probe at the latest (no PM domains should be attached/detached > after probe succeeds IOW), in which case it should be sufficient to do the > device_check_pm_callbacks() thing each time after probe successds. > > Thoughts? Ohh, I just realize that my comment was wrong. Sorry for the noise. Why genpd needs special treatment is to take care off the "non-probing" case. In other words when devices gets added to genpd directly by using the pm_genpd_add_device() API. Perhaps that deserves a comment though. > >> > out: >> > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c >> > index 1710c26ba097..5af45d20b677 100644 >> > --- a/drivers/base/power/main.c >> > +++ b/drivers/base/power/main.c >> > @@ -131,6 +131,8 @@ void device_pm_add(struct device *dev) >> > dev_name(dev->parent)); >> > list_add_tail(&dev->power.entry, &dpm_list); >> > mutex_unlock(&dpm_list_mtx); >> > + >> > + device_check_pm_callbacks(dev); >> > } >> > >> > /** >> > @@ -1569,6 +1571,11 @@ static int device_prepare(struct device *dev, pm_message_t state) >> > >> > dev->power.wakeup_path = device_may_wakeup(dev); >> > >> > + if (dev->power.no_pm_callbacks) { >> > + ret = 1; /* Let device go direct_complete */ >> > + goto unlock; >> > + } >> > + >> > if (dev->pm_domain) { >> > info = "preparing power domain "; >> > callback = dev->pm_domain->ops.prepare; >> > @@ -1591,6 +1598,7 @@ static int device_prepare(struct device *dev, pm_message_t state) >> > if (callback) >> > ret = callback(dev); >> > >> > +unlock: >> > device_unlock(dev); >> > >> > if (ret < 0) { >> > diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h >> > index 998fa6b23084..f665a7850016 100644 >> > --- a/drivers/base/power/power.h >> > +++ b/drivers/base/power/power.h >> > @@ -29,6 +29,8 @@ struct wake_irq { >> > extern void dev_pm_arm_wake_irq(struct wake_irq *wirq); >> > extern void dev_pm_disarm_wake_irq(struct wake_irq *wirq); >> > >> > +extern void device_check_pm_callbacks(struct device *dev); >> > + >> > #ifdef CONFIG_PM_SLEEP >> > >> > extern int device_wakeup_attach_irq(struct device *dev, >> > @@ -102,6 +104,10 @@ static inline void dev_pm_disarm_wake_irq(struct wake_irq *wirq) >> > { >> > } >> > >> > +static inline void device_check_pm_callbacks(struct device *dev) >> > +{ >> > +} >> > + >> > #endif >> > >> > #ifdef CONFIG_PM_SLEEP >> > diff --git a/include/linux/pm.h b/include/linux/pm.h >> > index 35d599e7250d..e334b9b8cd46 100644 >> > --- a/include/linux/pm.h >> > +++ b/include/linux/pm.h >> > @@ -566,6 +566,7 @@ struct dev_pm_info { >> > bool ignore_children:1; >> > bool early_init:1; /* Owned by the PM core */ >> > bool direct_complete:1; /* Owned by the PM core */ >> > + bool no_pm_callbacks:1; /* Owned by the PM core */ >> >> This flag is only being used while CONFIG_PM is set. I suggest we move >> within that ifdef. > > I guess you mean CONFIG_PM_SLEEP? Yes! Kind regards Uffe -- 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 30 September 2015 at 15:05, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > On Wednesday, September 30, 2015 01:33:29 PM Ulf Hansson wrote: >> On 30 September 2015 at 11:58, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote: >> > @@ -1369,6 +1372,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, >> > >> > genpd_free_dev_data(dev, gpd_data); >> > >> > + device_check_pm_callbacks(dev); >> > + >> > return 0; >> >> I can't tell whether this is an interesting feature to use for devices >> that gets attached to the ACPI PM domain. Although, you currently >> doesn't deal with that case, and too me I think this looks a bit >> weird/unsymmetrical. > > Good point. > > It needs to be done in every situation where a PM domain is or can be used. > > I guess we might require all PM domains to be attached to devices after > a successful probe at the latest (no PM domains should be attached/detached > after probe succeeds IOW), in which case it should be sufficient to do the > device_check_pm_callbacks() thing each time after probe successds. > > Thoughts? Sound good to me. How were you thinking of doing that? Manually checking that that's currently the case and adding a WARN() if a pm_domain is attached to a device that has been probed already? Thanks, Tomeu -- 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 Wednesday, September 30, 2015 03:59:48 PM Tomeu Vizoso wrote: > On 30 September 2015 at 15:05, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > On Wednesday, September 30, 2015 01:33:29 PM Ulf Hansson wrote: > >> On 30 September 2015 at 11:58, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote: > >> > @@ -1369,6 +1372,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, > >> > > >> > genpd_free_dev_data(dev, gpd_data); > >> > > >> > + device_check_pm_callbacks(dev); > >> > + > >> > return 0; > >> > >> I can't tell whether this is an interesting feature to use for devices > >> that gets attached to the ACPI PM domain. Although, you currently > >> doesn't deal with that case, and too me I think this looks a bit > >> weird/unsymmetrical. > > > > Good point. > > > > It needs to be done in every situation where a PM domain is or can be used. > > > > I guess we might require all PM domains to be attached to devices after > > a successful probe at the latest (no PM domains should be attached/detached > > after probe succeeds IOW), in which case it should be sufficient to do the > > device_check_pm_callbacks() thing each time after probe successds. > > > > Thoughts? > > Sound good to me. How were you thinking of doing that? Manually > checking that that's currently the case and adding a WARN() if a > pm_domain is attached to a device that has been probed already? I guess we need a function for setting/clearing the pm_domain pointer that will check whether or not the device has been probed and WARN() in that case. Then, convert all users of PM domains to use that function instead of manipulating the pointer directly. Thanks, Rafael -- 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 30 September 2015 at 23:17, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > On Wednesday, September 30, 2015 03:59:48 PM Tomeu Vizoso wrote: >> On 30 September 2015 at 15:05, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: >> > On Wednesday, September 30, 2015 01:33:29 PM Ulf Hansson wrote: >> >> On 30 September 2015 at 11:58, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote: >> >> > @@ -1369,6 +1372,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, >> >> > >> >> > genpd_free_dev_data(dev, gpd_data); >> >> > >> >> > + device_check_pm_callbacks(dev); >> >> > + >> >> > return 0; >> >> >> >> I can't tell whether this is an interesting feature to use for devices >> >> that gets attached to the ACPI PM domain. Although, you currently >> >> doesn't deal with that case, and too me I think this looks a bit >> >> weird/unsymmetrical. >> > >> > Good point. >> > >> > It needs to be done in every situation where a PM domain is or can be used. >> > >> > I guess we might require all PM domains to be attached to devices after >> > a successful probe at the latest (no PM domains should be attached/detached >> > after probe succeeds IOW), in which case it should be sufficient to do the >> > device_check_pm_callbacks() thing each time after probe successds. >> > >> > Thoughts? >> >> Sound good to me. How were you thinking of doing that? Manually >> checking that that's currently the case and adding a WARN() if a >> pm_domain is attached to a device that has been probed already? > > I guess we need a function for setting/clearing the pm_domain pointer that > will check whether or not the device has been probed and WARN() in that case. > > Then, convert all users of PM domains to use that function instead of > manipulating the pointer directly. Why would ever a device be fully probed without first having its PM domain pointer assigned? To me that wouldn't even work, as the device would rather depend on that the PM domain is power up to succeed being probed (at least in general case), and unless the PM domain pointer is set we can't control that. Kind regards Uffe -- 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 Thursday, October 01, 2015 11:04:17 AM Ulf Hansson wrote: > On 30 September 2015 at 23:17, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > On Wednesday, September 30, 2015 03:59:48 PM Tomeu Vizoso wrote: > >> On 30 September 2015 at 15:05, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > >> > On Wednesday, September 30, 2015 01:33:29 PM Ulf Hansson wrote: > >> >> On 30 September 2015 at 11:58, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote: > >> >> > @@ -1369,6 +1372,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, > >> >> > > >> >> > genpd_free_dev_data(dev, gpd_data); > >> >> > > >> >> > + device_check_pm_callbacks(dev); > >> >> > + > >> >> > return 0; > >> >> > >> >> I can't tell whether this is an interesting feature to use for devices > >> >> that gets attached to the ACPI PM domain. Although, you currently > >> >> doesn't deal with that case, and too me I think this looks a bit > >> >> weird/unsymmetrical. > >> > > >> > Good point. > >> > > >> > It needs to be done in every situation where a PM domain is or can be used. > >> > > >> > I guess we might require all PM domains to be attached to devices after > >> > a successful probe at the latest (no PM domains should be attached/detached > >> > after probe succeeds IOW), in which case it should be sufficient to do the > >> > device_check_pm_callbacks() thing each time after probe successds. > >> > > >> > Thoughts? > >> > >> Sound good to me. How were you thinking of doing that? Manually > >> checking that that's currently the case and adding a WARN() if a > >> pm_domain is attached to a device that has been probed already? > > > > I guess we need a function for setting/clearing the pm_domain pointer that > > will check whether or not the device has been probed and WARN() in that case. > > > > Then, convert all users of PM domains to use that function instead of > > manipulating the pointer directly. > > Why would ever a device be fully probed without first having its PM > domain pointer assigned? > > To me that wouldn't even work, as the device would rather depend on > that the PM domain is power up to succeed being probed (at least in > general case), and unless the PM domain pointer is set we can't > control that. That generally is the case, but then I can imagine a situation in which setting the pm_domain pointer after probe may work for somebody and my point is that we should enforce things that we are going to rely on for correctness rather then hope that everybody will do them just because they make sense. Thanks, Rafael -- 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/base/dd.c b/drivers/base/dd.c index be0eb4639128..fe0e9cb684b8 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -205,6 +205,8 @@ static void driver_bound(struct device *dev) klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); + device_check_pm_callbacks(dev); + /* * Make sure the device is no longer in one of the deferred lists and * kick off retrying all pending devices @@ -695,6 +697,7 @@ static void __device_release_driver(struct device *dev) dev->pm_domain->dismiss(dev); klist_remove(&dev->p->knode_driver); + device_check_pm_callbacks(dev); if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_UNBOUND_DRIVER, diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c index f32b802b98f4..1bba85f8bf8a 100644 --- a/drivers/base/power/common.c +++ b/drivers/base/power/common.c @@ -128,3 +128,30 @@ void dev_pm_domain_detach(struct device *dev, bool power_off) dev->pm_domain->detach(dev, power_off); } EXPORT_SYMBOL_GPL(dev_pm_domain_detach); + +static bool pm_ops_is_empty(const struct dev_pm_ops *ops) +{ + if (!ops) + return true; + + return !ops->prepare && + !ops->suspend && + !ops->suspend_late && + !ops->suspend_noirq && + !ops->resume_noirq && + !ops->resume_early && + !ops->resume && + !ops->complete; +} + +void device_check_pm_callbacks(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + dev->power.no_pm_callbacks = + (!dev->bus || pm_ops_is_empty(dev->bus->pm)) && + (!dev->class || pm_ops_is_empty(dev->class->pm)) && + (!dev->type || pm_ops_is_empty(dev->type->pm)) && + (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) && + (!dev->driver || pm_ops_is_empty(dev->driver->pm)); + spin_unlock_irq(&dev->power.lock); +} diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 16550c63d611..3cae1aa1885b 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -20,6 +20,8 @@ #include <linux/suspend.h> #include <linux/export.h> +#include "power.h" + #define GENPD_RETRY_MAX_MS 250 /* Approximate */ #define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \ @@ -1305,6 +1307,7 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); + device_check_pm_callbacks(dev); out: mutex_unlock(&genpd->lock); @@ -1369,6 +1372,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, genpd_free_dev_data(dev, gpd_data); + device_check_pm_callbacks(dev); + return 0; out: diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 1710c26ba097..5af45d20b677 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -131,6 +131,8 @@ void device_pm_add(struct device *dev) dev_name(dev->parent)); list_add_tail(&dev->power.entry, &dpm_list); mutex_unlock(&dpm_list_mtx); + + device_check_pm_callbacks(dev); } /** @@ -1569,6 +1571,11 @@ static int device_prepare(struct device *dev, pm_message_t state) dev->power.wakeup_path = device_may_wakeup(dev); + if (dev->power.no_pm_callbacks) { + ret = 1; /* Let device go direct_complete */ + goto unlock; + } + if (dev->pm_domain) { info = "preparing power domain "; callback = dev->pm_domain->ops.prepare; @@ -1591,6 +1598,7 @@ static int device_prepare(struct device *dev, pm_message_t state) if (callback) ret = callback(dev); +unlock: device_unlock(dev); if (ret < 0) { diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index 998fa6b23084..f665a7850016 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -29,6 +29,8 @@ struct wake_irq { extern void dev_pm_arm_wake_irq(struct wake_irq *wirq); extern void dev_pm_disarm_wake_irq(struct wake_irq *wirq); +extern void device_check_pm_callbacks(struct device *dev); + #ifdef CONFIG_PM_SLEEP extern int device_wakeup_attach_irq(struct device *dev, @@ -102,6 +104,10 @@ static inline void dev_pm_disarm_wake_irq(struct wake_irq *wirq) { } +static inline void device_check_pm_callbacks(struct device *dev) +{ +} + #endif #ifdef CONFIG_PM_SLEEP diff --git a/include/linux/pm.h b/include/linux/pm.h index 35d599e7250d..e334b9b8cd46 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -566,6 +566,7 @@ struct dev_pm_info { bool ignore_children:1; bool early_init:1; /* Owned by the PM core */ bool direct_complete:1; /* Owned by the PM core */ + bool no_pm_callbacks:1; /* Owned by the PM core */ spinlock_t lock; #ifdef CONFIG_PM_SLEEP struct list_head entry;
If a suitable prepare callback cannot be found for a given device and its driver has no PM callbacks at all, assume that it can go direct to complete when the system goes to sleep. The reason for this is that there's lots of devices in a system that do no PM at all and there's no reason for them to prevent their ancestors to do direct_complete if they can support it. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> --- Changes in v7: - Reduce indentation by adding a label in device_prepare() Changes in v6: - Add stub for !CONFIG_PM. - Move implementation of device_check_pm_callbacks to power/main.c as it doesn't belong to CONFIG_PM_SLEEP. - Take dev->power.lock before modifying flag. Changes in v5: - Check for all dev_pm_ops instances associated to a device, updating a no_pm_callbacks flag at the times when that could change. drivers/base/dd.c | 3 +++ drivers/base/power/common.c | 27 +++++++++++++++++++++++++++ drivers/base/power/domain.c | 5 +++++ drivers/base/power/main.c | 8 ++++++++ drivers/base/power/power.h | 6 ++++++ include/linux/pm.h | 1 + 6 files changed, 50 insertions(+)