On 29.01.2016 21:36, Daniel Stone wrote: > On 29 January 2016 at 03:44, Michel Dänzer <mic...@daenzer.net> wrote: >> It still sounds like significant work (particularly for somebody like me >> who isn't very familiar with Wayland details yet). It should be done by >> somebody who cares about the difference you're describing. I think it's >> unreasonable to expect myself or Axel to do it, especially since you >> said on IRC: >> >> 08:35 #dri-devel: < daniels> mannerov: it makes the flag totally >> meaningless - s/SCANOUT/NOT_A_FBO/ and i'll ack it >> >> Which makes little sense to me — even if the SCANOUT flags aren't used >> optimally yet, their meaning is quite clear. > > It's nothing to do with Wayland really. > > The core problem is that: > a) buffer allocation is incompletely described over the wire (AFAICT, > tiling is enabled for that buffer, but the combination of RGB format + > 0 modifier implies a purely linear format),
What does "the wire" refer to here, if not the Wayland protocol? > which prevents an exacerbating problem from being properly fixed: > b) the Gallium gbm implementation does not reject tiled buffers when > importing to a display which cannot show tiled buffers > and you are proposing a hack: > c) pessimise all winsys allocations to the lowest common denominator: > avoiding tiling by mandating they be scanout-compatible scanout-compatible doesn't imply no tiling, but other than that, sounds about right. > It works I guess, but until a and b are fixed, performance is going to > be suboptimal - again, if there was no performance impact to these > allocations, then they would always just happen by default. So, which driver(s) in Mesa right now would be affected by this, and how? > Merging the hack makes it impossible for non-Gallium drivers to have a > and b correct (I'm not sure off the top of my head whether they are > correct or whether we just get lucky on allocations), As I said before, looking at intel_validate_usage, I suspect the latter. > because as soon as those are fixed, we can't remove the scanout flag without > breaking > Gallium until it also fixes those two. And it seems like that's > exceedingly unlikely to happen, [...] Why is that? I wouldn't mind looking into fixing the Gallium specific parts. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
