<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [SNB] INTEL_DEBUG=nohiz is likely broken for depth/stencil buffers" href="https://bugs.freedesktop.org/show_bug.cgi?id=109985#c14">Comment # 14</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [SNB] INTEL_DEBUG=nohiz is likely broken for depth/stencil buffers" href="https://bugs.freedesktop.org/show_bug.cgi?id=109985">bug 109985</a> from <a class="email" href="mailto:nanleychery@gmail.com" title="Nanley Chery <nanleychery@gmail.com>"> Nanley Chery</a> <pre>(In reply to Nanley Chery from <a href="show_bug.cgi?id=109985#c13">comment #13</a>) > (In reply to asimiklit from <a href="show_bug.cgi?id=109985#c12">comment #12</a>) > > (In reply to Nanley Chery from <a href="show_bug.cgi?id=109985#c0">comment #0</a>) > > > For SNB, INTEL_DEBUG=nohiz seems to be broken in two places: > > > > > > 1. In miptree_create() in intel_mipmap_tree.c. Trying to create a > > > depth/stencil buffer will cause a depth miptree to be created without > > > stencil. > > > > As far as found this code disallows us to create combined depth/stencil on > > SNB: > > mesa_format mt_fmt = format; > > if (!_mesa_is_format_color_format(format) && devinfo->gen >= 6) { > > /* Fix up the Z miptree format for how we're splitting out separate > > * stencil. Gen7 expects there to be no stencil bits in its depth > > buffer. > > */ > > mt_fmt = intel_depth_format_for_depthstencil_format(format); > > } > > > > Note: This code just replaces MESA_FORMAT_Z24_UNORM_S8_UINT by > > MESA_FORMAT_Z24_UNORM_X8_UINT > > but in this case 'mt_surf_usage' does not return a > > ISL_SURF_USAGE_STENCIL_BIT and that leads to > > an assertion: assert(src_surf->surf->usage & > > ISL_SURF_USAGE_STENCIL_BIT); in a blorp_blit function. > > PS: Actually I didn't check if this assertion actually matter. > > > > But just avoiding of this code doesn't make us happy too ( > > Because we fail a choosing of a surf tiling method and > > "isl_surf_choose_tiling" always returns false. > > > > Now I am investigates a SNB PRM for the valid combinations of tiling methods > > with combined depth/stencil. > > > > Any advices or suggestions are welcome :) > > > > The cause of this problem is that we have two non-equivalent conditions for > selecting the main miptree format and creating a separate stencil miptree: > The condition you mentioned above and the call to needs_separate_stencil(). > One solution is to refactor and reuse needs_separate_stencil() for the > format selection. > Sorry, I only addressed the problem with avoiding the format selection code. The tiling issue you've pointed out is a bug in isl_gen6_filter_tiling(). For depth-stencil buffers on SNB, we have a Y-tiled surface with the elements laid out as described in the "3D Depth Buffer Surfaces" section of the PRM.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>