On Friday, July 08, 2011, Rafael J. Wysocki wrote: ... > > Well, in fact, since we already have .active_wakeup(), what about the > following patch (on top of https://lkml.org/lkml/2011/7/8/223): Well, it is wrong, because we've been discussing devices that are _not_ enabled to wake up the system. > --- > drivers/base/power/domain.c | 4 ++++ > 1 file changed, 4 insertions(+) > > Index: linux-2.6/drivers/base/power/domain.c > =================================================================== > --- linux-2.6.orig/drivers/base/power/domain.c > +++ linux-2.6/drivers/base/power/domain.c > @@ -519,6 +519,10 @@ static int pm_genpd_prepare(struct devic > return -EBUSY; > } > > + if (device_may_wakeup(dev) So, this should have been !device_may_wakeup(dev), _but_ ... > + && !(genpd->active_wakeup && genpd->active_wakeup(dev))) > + pm_runtime_resume(dev); > + > genpd_acquire_lock(genpd); > > if (genpd->prepared_count++ == 0) There's one more case to consider, namely devices that are runtime suspended, set up to wake up the system from sleep states (ie. device_may_wakeup(dev) returns "true") and such that genpd->active_wakeup(dev) returns "true" for them, because they need to be resumed at this point too (arguably, it makes a little sense to runtime suspend such devices, but that's possible in principle). So, IMO, the patch should look like this: --- drivers/base/power/domain.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) Index: linux-2.6/drivers/base/power/domain.c =================================================================== --- linux-2.6.orig/drivers/base/power/domain.c +++ linux-2.6/drivers/base/power/domain.c @@ -486,6 +486,22 @@ static void pm_genpd_sync_poweroff(struc } /** + * resume_needed - Check whether to resume a device before system suspend. + * @dev: Device to handle. + * @genpd: PM domain the device belongs to. + */ +static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd) +{ + bool active_wakeup; + + if (!device_can_wakeup(dev)) + return false; + + active_wakeup = genpd->active_wakeup && genpd->active_wakeup(dev); + return device_may_wakeup(dev) ? active_wakeup : !active_wakeup; +} + +/** * pm_genpd_prepare - Start power transition of a device in a PM domain. * @dev: Device to start the transition of. * @@ -519,6 +535,9 @@ static int pm_genpd_prepare(struct devic return -EBUSY; } + if (resume_needed(dev, genpd)) + pm_runtime_resume(dev); + genpd_acquire_lock(genpd); if (genpd->prepared_count++ == 0) _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
