> I've discussed drm props and ABI requirements a bit with Dave on irc. > In the past we've been pretty lax with properties since connector > properties are mostly meant for end-users to set manually, so not > really much point in standardizing and treating them like ABI. But now > we have props for plane/CRTC and atomic and those are really meant to > be used by compositors, so all the problems with ABI start to kick in. > And we had them already, e.g. early i915 patches for rotation where cw > while existing omap supports was ccw. I also just spotted msm patches > which reinvent the mirror flags of the rotation prop with their own > flip prop. And there's a lot of things in-progress already like > zpos/alpha/blending props, color manager/per-plane gamma, ... > > To avoid future ABI disaster I think we should treat these props like > any other drm ABI and require full-blown userspace, so here that would > be a real implementation in something like weston, -modesetting, the > new cros thing or maybe even hwc if that ever happens as an > open-source project. And test tools like modetest don't cut it since > upside down desktop is obvious, upside down test pattern meh. And > modetest doesn't bother with all the TEST_ONLY and failure recory > stuff like e.g. weston atomic needs to. > > Internally I think we should also try to standarize prop handling by > pushing them into drm_*_state structs and adding decoding in core and > good helpers. And hopefully soon we have markdown for kerneldoc so can > transform that horrible docbook table into something sane. But that's > just internals which we can always fix. ABI's forever. > > Anyway this is all kinda just clarification at least for i915. props > for compositors are ABI like anything else, same rules still apply. Yes totally, no adding props for closed compositors as well if we can't use it with weston/mutter/open source stuff we can't test it. (are there any closed source compositors?) Dave. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
