On Wed, Oct 14, 2015 at 11:39:03AM +0200, Neil Roberts wrote: > Ben Widawsky <benjamin.widaw...@intel.com> writes: > > > The impetus for this patch comes from a seemingly benign statement within > > the > > spec (quoted within the patch). For me, this patch was at some point > > critical > > for getting stable piglit results (though this did not seem to be the case > > on a > > branch Chad was working on). > > > > It is very important for clearing multiple color buffer attachments and can > > be > > observed in the following piglit tests: > > spec/arb_framebuffer_object/fbo-drawbuffers-none glclear > > spec/ext_framebuffer_multisample/blit-multiple-render-targets 0 > > > > Signed-off-by: Ben Widawsky <b...@bwidawsk.net> > > --- > > src/mesa/drivers/dri/i965/brw_meta_fast_clear.c | 97 > > +++++++++++++++++++++---- > > 1 file changed, 84 insertions(+), 13 deletions(-) > > > > diff --git a/src/mesa/drivers/dri/i965/brw_meta_fast_clear.c > > b/src/mesa/drivers/dri/i965/brw_meta_fast_clear.c > > index 7bf52f0..9e6711e 100644 > > --- a/src/mesa/drivers/dri/i965/brw_meta_fast_clear.c > > +++ b/src/mesa/drivers/dri/i965/brw_meta_fast_clear.c > > @@ -427,6 +427,74 @@ use_rectlist(struct brw_context *brw, bool enable) > > brw->ctx.NewDriverState |= BRW_NEW_FRAGMENT_PROGRAM; > > } > > > > +/** > > + * Individually fast clear each color buffer attachment. On previous gens > > this > > + * isn't required. The motivation for this comes from one line (which > > seems to > > + * be specific to SKL+). The list item is in section titled _MCS Buffer for > > + * Render Target(s)_ > > + * > > + * "Since only one RT is bound with a clear pass, only one RT can be > > cleared > > + * at a time. To clear multiple RTs, multiple clear passes are required." > > This sentence also appears in the HSW PRM so it seems a bit odd if it's > only causing problems on SKL. I guess if we get Piglit regressions > without it then it makes sense to have the patch. It might be worth just > double checking whether this patch is completely necessary. The wording > in the commit message seems a little unsure.
The spec seems to be missing something as the section discussing "Render Target Fast Clear" seems to suggest the opposite: "The render target(s) is/are bound as they normally would be, with the MCS surface defined in SURFACE_STATE." _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
