Messages in this thread | | | Subject | Re: [PATCH 2/3] [SCSI]: runtime resume parent for child's system-resume | From | Lin Ming <> | Date | Thu, 15 Dec 2011 02:31:52 +0800 |
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On Thu, 2011-12-15 at 00:51 +0800, Alan Stern wrote: > On Wed, 14 Dec 2011, Lin Ming wrote: > > > On Wed, Dec 14, 2011 at 11:18 AM, Lin Ming <ming.m.lin@intel.com> 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@intel.com> > > > > Hi Alan, > > > > May I add your SOB? > > You can add: Acked-by: Alan Stern <stern@rowland.harvard.edu> > > Did you test this? Does it do what you want?
Yes, I have tested this and it fixes the problem.
Thanks.
> > Alan Stern >
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