On Tuesday, January 15, 2013 11:26:11 PM Chuansheng Liu wrote: > > For the case that in rpm_suspend() and deferred_resume is true, > the rpm_resume() will be called, and if rpm_resume() return error, > at this time, the device is still in SUSPENDED state. > > In this case it is still an suspend succeeding case, we should > return non-error instead of EAGAIN. > > An example like below for this case: > CPU1: CPU2: > pm_runtime_get_sync() > pm_runtime_put_sync_suspend() > rpm_suspend() > __update_runtime_status(dev, RPM_SUSPENDING) > rpm_callback() > spin_unlock_irq() > ... pm_runtime_get() > > spin_lock_irqsave() > cb() rpm_resume() > ... > dev->power.deferred_resume = true > > spin_unlock_irqrestore() > spin_lock_irq() > __update_runtime_status(dev, RPM_SUSPENDED) > rpm_resume() is called due to deferred_resume is true > > Here if rpm_resume() failed in CPU1, the runtime_status is still SUSPENDED, > we should return 0 in this case.
No, we shouldn't. Please note that rpm_resume() may fail for multiple reasons and some of them actually mean real errors, in which case we shouldn't return 0, because that may confuse the caller. However, if we return -EAGAIN regardless, whatever the caller does next will be fine. Thanks, Rafael > Signed-off-by: liu chuansheng <[email protected]> > --- > drivers/base/power/runtime.c | 8 +++++--- > 1 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > index 3148b10..0adc713 100644 > --- a/drivers/base/power/runtime.c > +++ b/drivers/base/power/runtime.c > @@ -436,9 +436,11 @@ static int rpm_suspend(struct device *dev, int rpmflags) > > if (dev->power.deferred_resume) { > dev->power.deferred_resume = false; > - rpm_resume(dev, 0); > - retval = -EAGAIN; > - goto out; > + if (rpm_resume(dev, 0) >= 0) { > + /* In case resuming succeeded, return EAGAIN error */ > + retval = -EAGAIN; > + goto out; > + } > } > > /* Maybe the parent is now able to suspend. */ > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
