On Mon, Jun 15, 2015 at 11:18:46AM +0200, Maarten Lankhorst wrote: > Op 15-06-15 om 11:13 schreef Daniel Vetter: > > On Mon, Jun 15, 2015 at 09:30:19AM +0200, Maarten Lankhorst wrote: > >> Op 15-06-15 om 09:10 schreef Daniel Vetter: > >>> On Fri, Jun 12, 2015 at 11:18:22AM +0200, Maarten Lankhorst wrote: > >>>> In intel it's useful to keep track of some state changes with old > >>>> crtc state vs new state, for example to disable initial planes or > >>>> when a modeset's prevented during fastboot. > >>>> > >>>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > >>> Hm, thus far the approach has been that the various ->check callbacks diff > >>> the state and set appropriate stuff like needs_modeset or planes_changed. > >>> And with intel_crtc->atomic we've kinda started to build up similar > >>> things for i915. What do you plan to use this for? > >>> -Daniel > >> On a modeset I want to disable all old planes by calling plane->disable_plane, which is old_crtc_state->plane_mask. > >> This is for initial hw readout, where a plane might be active without a fb set. I want to run it during vblank evasion if possible, which > >> means in atomic_begin or flush. > >> > >> commit_plane is not called if the old and new state both have a NULL fb, so the initial plane would stay active in this case. > > Hm, so this is for the i915 state readout code. Imo we shouldn't ever leak > > this out of the state readout code but instead sanitize the plane state to > > make sense. Roughly this would be: > > - read out crtc state > > - try to reconstruct initial fb for primary plane, if this succeeds then > > fully link up the plane with the crtc in the plane_state. > Agreed. Right now get_initial_plane_config takes an initial_plane_state, could we make this atomic too? The initial fb takeover code is a bit tricky since we need to temporarily store a few things while not everything is set up yet fully. We could try to move that information into the plane state, but it would duplicate existing information stored in state->fb->i915_gem_object. Not sure whether it's worth it to have something fully atomic for plane state readout. The other option would be to allow enabled planes without a full-blown fb object, but experience says this leads to piles of drama in the watermark code. > > > - then walk all planes for the crtc, and if any plane is enabled in the hw > > state but doesn't have fb/crtc set in the plane_state force-disable it. > Can we disable those planes without penalty? Some of them call watermark update, this is a bug but still.. What kind of penalty do you think of? Performance doesn't matter since if we get a bad state and need to frob planes around we'll likely also need a full modeset anyway. Wrt watermark updates that needs to be avoided ofc, so similar to the "force disable all planes in crtc_disable" problem. We might be able to reuse a bit of code for that. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
