On Wed, 14 Dec 2011, Lin Ming wrote: > On Wed, Dec 14, 2011 at 11:18 AM, Lin Ming <ming.m.lin@xxxxxxxxx> wrote: > > [Patch description from Alan Stern] > > > > If a child device was runtime-suspended when a system suspend began, > > then there will be nothing to prevent its parent from > > runtime-suspending as soon as it is woken up during the system resume. > > Then when the time comes to resume the child, the resume will fail > > because the parent is already back at low power. > > > > On the other hand, there are some devices which should remain at low > > power across an entire suspend-resume cycle. �The details depend on the > > device and the platform. > > > > This suggests that the PM core is not the right place to solve the > > problem. �One possible solution is for the subsystem or device driver > > to call pm_runtime_get_sync(dev->parent) at the start of the > > system-resume procedure and pm_runtime_put_sync(dev->parent) at the > > end. > > > > Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx> > > Hi Alan, > > May I add your SOB? You can add: Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Did you test this? Does it do what you want? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
