On Mon, Oct 29, 2018 at 04:00:04PM -0700, Eric Anholt wrote: > Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> writes: > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > Add a function to check whether there is at least one plane that > > supports a specific format and modifier combination. Drivers can > > use this to reject unsupported formats/modifiers in .fb_create(). > > > > v2: Accept anyformat if the driver doesn't do planes (Eric) > > s/planes_have_format/any_plane_has_format/ (Eric) > > Check the modifier as well since we already have a function > > that does both > > v3: Don't do the check in the core since we may not know the > > modifier yet, instead export the function and let drivers > > call it themselves > > > > Cc: Eric Anholt <eric@xxxxxxxxxx> > > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> > > I don't particularly see the point in having FB creation duplicate the > validation that atomic check will eventually do, and it means that FB > creation cost scales with plane count, but if i915's going to do this, > it seems reasonable for them. atomic_check checks for a given plane only, I do think it makes sense to make sure you can't create framebuffers that are impossible to use on a given driver at addfb time. In case the overhead is ever critical, we could compile a static map of this at driver load time, and then check that. Aside: Shouldn't we make this the default for atomic drivers? With atomic drivers we can assume that all planes have valid format lists (because atomic_check checks them already). Only with non-atomic drivers, how might have a faked primary plane is this not a valid assumption ... -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
