Messages in this thread | | | Date | Tue, 22 Sep 2015 10:15:02 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [RFC PATCH] PM / Runtime: runtime: Add sysfs option for forcing runtime suspend |
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On Tue, 22 Sep 2015, Oliver Neukum wrote:
> Indeed. We can handle output to suspended devices by waking them. > I don't see why this case is different. We are talking about input > only. > > > The runtime-PM "usage" value for these devices is a little tricky to > > calculate. It should be nonzero if there are any open files _and_ the > > device isn't "inhibited". I don't know the best way to represent that > > kind of condition in the runtime PM framework. > > Does that make sense in the generic framework at all? I still > think that drivers should cease IO for input in such cases. > That should involve a common callback, but no counter.
I'm not sure I understand what you're saying. Are you suggesting that this "inhibit" mechanism should involve a new callback different from the existing runtime-PM callbacks? And when this new callback is invoked, drivers should cancel existing input requests (these devices are input-only) and go to low power?
This would create a parallel runtime-PM mechanism which is independent of the existing one. Is that really a good idea?
Alan Stern
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