On Wed, Sep 2, 2020 at 2:49 PM Simon Ser <contact@xxxxxxxxxxx> wrote: > > On Wednesday, September 2, 2020 2:44 PM, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote: > > > > I suppose something similar happens in user-space: gbm_bo_create > > > without modifiers needs to properly set the implicit modifier, ie. > > > gbm_bo_get_modifier needs to return the effective modifier. Is this > > > something already documented? > > > > I don't think that happens, but it has come up in discussions. It's > > kinda different scenario though: getfb2 is for cross-compositor stuff, > > enabling smooth transitions at boot-up and when switching. So you have > > a legit reason for mixing modifier-aware userspace with > > non-modifier-aware userspace. And the modifier-aware userspace would > > like that everything works with modifiers consistently, including > > getfb2. But gbm is just within a single process, and that should > > either run all with modifiers, or not at all, since these worlds just > > dont mix well. Hence I'm not seeing much use for that, -modesetting > > being a confused mess nonwithstanding :-) > > Well… There's also the case where some legacy Wayland client talks to a > modifier-aware compositor. gbm_bo_import would be called without a > modifier, but the compositor expects gbm_bo_get_modifier to work. > > Also, wlroots will call gbm_bo_create without a modifier to only let > the driver pick "safe" modifiers in case passing the full list of > modifiers results in a black screen. Later on wlroots will call > gbm_bo_get_modifier to figure out what modifier the driver picked. I don't think we can do that generally, as pre-modifier clients are typically also not capable of handling memory planes > format planes, which will happen with compression (but used out of band communication for the second plane on AMD in the non-modifier case). > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
