Messages in this thread | | | From | Laurent Pinchart <> | Subject | Re: [PATCH v3 1/2] PM / sleep: Let devices force direct_complete | Date | Fri, 17 Apr 2015 18:35:05 +0300 |
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Hi Tomeu,
Thank you for the patch.
On Friday 17 April 2015 17:24:49 Tomeu Vizoso wrote: > Introduce a new per-device flag power.force_direct_complete that will > instruct the PM core to ignore the runtime PM status of its descendants > when deciding whether to let this device remain in runtime suspend when > the system goes into a sleep power state. > > This is needed because otherwise it would be needed to get dozens of > drivers to implement the prepare() callback and be runtime PM active > even if they don't have a 1-to-1 relationship with a piece of HW.
I'll let PM experts comment on the approach, but I believe the new flag would benefit from being documented (likely in Documentation/power/devices.txt) :-)
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> > --- > drivers/base/power/main.c | 13 +++++++++---- > include/linux/pm.h | 1 + > 2 files changed, 10 insertions(+), 4 deletions(-) > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > index 3d874ec..728c2dc 100644 > --- a/drivers/base/power/main.c > +++ b/drivers/base/power/main.c > @@ -1438,7 +1438,9 @@ static int __device_suspend(struct device *dev, > pm_message_t state, bool async) if (parent) { > spin_lock_irq(&parent->power.lock); > > - dev->parent->power.direct_complete = false; > + if (!dev->parent->power.force_direct_complete) > + dev->parent->power.direct_complete = false; > + > if (dev->power.wakeup_path > && !dev->parent->power.ignore_children) > dev->parent->power.wakeup_path = true; > @@ -1605,9 +1607,12 @@ static int device_prepare(struct device *dev, > pm_message_t state) * will do the same thing with all of its descendants". > This only * applies to suspend transitions, however. > */ > - spin_lock_irq(&dev->power.lock); > - dev->power.direct_complete = ret > 0 && state.event == PM_EVENT_SUSPEND; > - spin_unlock_irq(&dev->power.lock); > + if (state.event == PM_EVENT_SUSPEND) { > + spin_lock_irq(&dev->power.lock); > + dev->power.direct_complete = ret > 0 || > + dev->power.force_direct_complete; > + spin_unlock_irq(&dev->power.lock); > + } > return 0; > } > > diff --git a/include/linux/pm.h b/include/linux/pm.h > index 2d29c64..2e41cfd 100644 > --- a/include/linux/pm.h > +++ b/include/linux/pm.h > @@ -553,6 +553,7 @@ 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 force_direct_complete:1; > spinlock_t lock; > #ifdef CONFIG_PM_SLEEP > struct list_head entry;
-- Regards,
Laurent Pinchart
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