Hi Thierry, On Fri, 25 Oct 2019 at 12:36, Thierry Reding <thierry.reding@xxxxxxxxx> wrote: > On Thu, Oct 24, 2019 at 01:45:16PM -0700, Rajat Jain wrote: > > I did think about having a state variable in software to get and set > > this. However, I think it is not very far fetched that some platforms > > may have "hardware kill" switches that allow hardware to switch > > privacy-screen on and off directly, in addition to the software > > control that we are implementing. Privacy is a touchy subject in > > enterprise, and anything that reduces the possibility of having any > > inconsistency between software state and hardware state is desirable. > > So in this case, I chose to not have a state in software about this - > > we just report the hardware state everytime we are asked for it. > > So this doesn't really work with atomic KMS, then. The main idea behind > atomic KMS is that you apply a configuration either completely or not at > all. So at least for setting this property you'd have to go through the > state object. > > Now, for reading out the property you might be able to get away with the > above. I'm not sure if that's enough to keep the state up-to-date, > though. Is there some way for a kill switch to trigger an interrupt or > other event of some sort so that the state could be kept up-to-date? > > Daniel (or anyone else), do you know of any precedent for state that > might get modified behind the atomic helpers' back? Seems to me like we > need to find some point where we can actually read back the current > "hardware value" of this privacy screen property and store that back > into the state. Well, apart from connector state, though that isn't really a property as such, there's the link_state property, which is explicitly designed to do just that. That has been quite carefully designed for the back-and-forth though. Cheers, Daniel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
