On Tue, Jan 05, 2016 at 05:18:40PM +0200, Ville Syrjälä wrote: > On Tue, Jan 05, 2016 at 03:50:38PM +0100, Daniel Vetter wrote: > > On Mon, Jan 04, 2016 at 07:06:15PM +0200, Ville Syrjälä wrote: > > > On Mon, Jan 04, 2016 at 11:16:39AM +0100, Maarten Lankhorst wrote: > > > > Hey, > > > > > > > > Op 23-12-15 om 12:05 schreef Nabendu Maiti: > > > > > This patch is adding pipesource size as property as intel property.User > > > > > application is allowed to change the pipe source size in runtime on BXT/SKL. > > > > > Added the property as inteli crtc property. > > > > > > > > > > Comments and suggestions are requested for whether we can keep the > > > > > property as intel crtc property or move to drm level. > > > > > > > > > This property would get lost on a modeset. But why do you need a pipe_src property? > > > > > > It's needed if we want to use the panel fitter with non-eDP/LVDS/DSI > > > displays. > > > > > > Last time this came up I decided that we want to expose this via a new > > > "fixed_mode" property. Ie. userspace can choose the actual display > > > timings by setting the "fixed_mode" property with a specific mode, and > > > then the normal mode property will basically just control just the pipe > > > src size just like it already does for eDP/LVDS/DSI where we already have > > > the fixed_mode internally (just not exposed to usersapce). If the > > > fixed_mode is not specified, things will work just as they do right > > > now. Obviously for eDP/LVDS/DSI we will reject any request to > > > change/unset the fixed mode. > > > > > > The benefit of that approach is that things will work exactly the same > > > way as before unless the user explicitly sets the fixed_mode, and once > > > it's set thigns will work exactly the same way as they have worked so > > > far for eDP/LVDS/DSI. Also it keeps the policy of choosing the fixed > > > mode strictly is userspace for external displays. > > > > > > And as a bonus we will also expose the eDP/LVDS/DSI fixed_mode to > > > userspace giving userspace more information on what the actual panel > > > timings are. Currently userspace has to more or less guess that one > > > of the modes the connector claims to support has the actual panel > > > timings. > > > > > > So far I've not heard any opposing opinions to this plan. > > > > Hm yeah, pipe_src would run into all kinds of fun in conjunction with the > > existing fixed mode stuff we have. Just exposing the fixed as a prop might > > be simpler. But then we need to figure out what to do wrt the clock in the > > mode passed in through userspace - currently the fixed mode always wins, > > but for manual DRRS it would be nice if userspace could control it, and > > doesn't have to know that there's a fixed_mode. > > We could have the user mode vrefresh indicate the desired refresh rate > of the fixed mode as well. In fact I've been wanting to add a check to > make sure the user mode refresh rate isn't too far off from the > fixed/downlclock mode vrefresh, but didn't get around to it yet. Yeah agreed, userspace vrefresh should control (or at least be checked against) the fixed mode vrefresh. > > So semantically I think only exposing the pipe src to expose panel fitters > > would be cleaner. Then we'd need to deal with some internal troubles to > > make sure we combine everything correctly, but that shouldn't be too hard > > really. > > I think it's quite a bit more work since we have to redo all the fb size > checks and whatnot to use the property when specified. I once outlined > a more detailed plan for his approach too (too lazy to dig up the mail), > but I think the fixed mode prop is a simpler approach and won't actually > require much in the way of userspace changes either. It'll be enough to > set the property once and then even the legacy modeset ioctls will work > exactly like they do now for eDP/LVDS/DSI. One downside of the fixed mode against an explicit pipe src rectangle is that the explict rectangle allows us to letter/pillar/stretch/move too. With just a fixed_mode that's much harder to pull off. I think for i915 it should be fairly ok-ish to implement this. We just need to move pipe src rectangle to drm_crtc_state, and adjust all the pfit config logic to work on the pipe level. Panels would then only replace the output mode with the fixed panel mode, and leave scaling/pfit selection to the core crtc code. -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
