On Tue, Sep 27, 2016 at 03:12:17PM -0700, Chad Versace wrote: > On Tue 27 Sep 2016, Nanley Chery wrote: > > On Tue, Sep 27, 2016 at 11:00:21AM -0700, Chad Versace wrote: > > > > As a consequence of that reasoning, we should set > > > 3DSTATE_CLEAR_PARAMS.DepthClearValueValid = 1 > > > whenever hiz is enabled, even if we don't care about the actual clear > > > value. > > > > In the V3, I plan to emit that packet once at device initialization time > > HSW+, and to always emit it (in the expected location) for IVB/BYT. Only > > the latter platforms have the restriction that it must always be > > programmed with the other depth/stencil commands. > > Is there any benefit to emitting it multiple times on ivb/byt? Does > emitting once during initialization, as for hsw, also work for ivb/byt? > If so, the code is cleaner if the two gens share the same workaround > code.
The benefit for emitting it multiple times on IVB/BYT is that we're (possibly) following the oddly-worded programming note for the packet: From the IVB PRM Vol2P1, 11.5.5.4 3DSTATE_CLEAR_PARAMS: 3DSTATE_CLEAR_PARAMS must always be programmed in the along with the other Depth/Stencil state commands(i.e. 3DSTATE_DEPTH_BUFFER, 3DSTATE_STENCIL_BUFFER, or 3DSTATE_HIER_DEPTH_BUFFER) HSW+ doesn't have this restriction, so we're free to only do it once. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev