src/mesa/drivers/dri/i965/gen8_depth_state.c

   1 /*
   2  * Copyright © 2011 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include "intel_batchbuffer.h"
  25 #include "intel_mipmap_tree.h"
  26 #include "intel_fbo.h"
  27 #include "intel_resolve_map.h"
  28 #include "brw_context.h"
  29 #include "brw_state.h"
  30 #include "brw_defines.h"
  31 #include "brw_wm.h"
  32
  33 /**
  34  * Helper function to emit depth related command packets.
  35  */
  36 static void
  37 emit_depth_packets(struct brw_context *brw,
  38                    struct intel_mipmap_tree *depth_mt,
  39                    uint32_t depthbuffer_format,
  40                    uint32_t depth_surface_type,
  41                    bool depth_writable,
  42                    struct intel_mipmap_tree *stencil_mt,
  43                    bool stencil_writable,
  44                    uint32_t stencil_offset,
  45                    bool hiz,
  46                    uint32_t width,
  47                    uint32_t height,
  48                    uint32_t depth,
  49                    uint32_t lod,
  50                    uint32_t min_array_element)
  51 {
  52    uint32_t mocs_wb = brw->gen >= 9 ? SKL_MOCS_WB : BDW_MOCS_WB;
  53
  54    /* Skip repeated NULL depth/stencil emits (think 2D rendering). */
  55    if (!depth_mt && !stencil_mt && brw->no_depth_or_stencil) {
  56       assert(brw->hw_ctx);
  57       return;
  58    }
  59
  60    intel_emit_depth_stall_flushes(brw);
  61
  62    /* _NEW_BUFFERS, _NEW_DEPTH, _NEW_STENCIL */
  63    BEGIN_BATCH(8);
  64    OUT_BATCH(GEN7_3DSTATE_DEPTH_BUFFER << 16 | (8 - 2));
  65    OUT_BATCH(depth_surface_type << 29 |
  66              (depth_writable ? (1 << 28) : 0) |
  67              (stencil_mt != NULL && stencil_writable) << 27 |
  68              (hiz ? 1 : 0) << 22 |
  69              depthbuffer_format << 18 |
  70              (depth_mt ? depth_mt->pitch - 1 : 0));
  71    if (depth_mt) {
  72       OUT_RELOC64(depth_mt->bo,
  73                   I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER, 0);
  74    } else {
  75       OUT_BATCH(0);
  76       OUT_BATCH(0);
  77    }
  78    OUT_BATCH(((width - 1) << 4) | ((height - 1) << 18) | lod);
  79    OUT_BATCH(((depth - 1) << 21) | (min_array_element << 10) | mocs_wb);
  80    OUT_BATCH(0);
  81    OUT_BATCH(((depth - 1) << 21) | (depth_mt ? depth_mt->qpitch >> 2 : 0));
  82    ADVANCE_BATCH();
  83
  84    if (!hiz) {
  85       BEGIN_BATCH(5);
  86       OUT_BATCH(GEN7_3DSTATE_HIER_DEPTH_BUFFER << 16 | (5 - 2));
  87       OUT_BATCH(0);
  88       OUT_BATCH(0);
  89       OUT_BATCH(0);
  90       OUT_BATCH(0);
  91       ADVANCE_BATCH();
  92    } else {
  93       BEGIN_BATCH(5);
  94       OUT_BATCH(GEN7_3DSTATE_HIER_DEPTH_BUFFER << 16 | (5 - 2));
  95       OUT_BATCH((depth_mt->hiz_buf->pitch - 1) | mocs_wb << 25);
  96       OUT_RELOC64(depth_mt->hiz_buf->bo,
  97                   I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER, 0);
  98       OUT_BATCH(depth_mt->hiz_buf->qpitch >> 2);
  99       ADVANCE_BATCH();
 100    }
 101
 102    if (stencil_mt == NULL) {
 103      BEGIN_BATCH(5);
 104       OUT_BATCH(GEN7_3DSTATE_STENCIL_BUFFER << 16 | (5 - 2));
 105       OUT_BATCH(0);
 106       OUT_BATCH(0);
 107       OUT_BATCH(0);
 108       OUT_BATCH(0);
 109       ADVANCE_BATCH();
 110    } else {
 111       BEGIN_BATCH(5);
 112       OUT_BATCH(GEN7_3DSTATE_STENCIL_BUFFER << 16 | (5 - 2));
 113       /* The stencil buffer has quirky pitch requirements.  From the Graphics
 114        * BSpec: vol2a.11 3D Pipeline Windower > Early Depth/Stencil Processing
 115        * > Depth/Stencil Buffer State > 3DSTATE_STENCIL_BUFFER [DevIVB+],
 116        * field "Surface Pitch":
 117        *
 118        *    The pitch must be set to 2x the value computed based on width, as
 119        *    the stencil buffer is stored with two rows interleaved.
 120        *
 121        * (Note that it is not 100% clear whether this intended to apply to
 122        * Gen7; the BSpec flags this comment as "DevILK,DevSNB" (which would
 123        * imply that it doesn't), however the comment appears on a "DevIVB+"
 124        * page (which would imply that it does).  Experiments with the hardware
 125        * indicate that it does.
 126        */
 127       OUT_BATCH(HSW_STENCIL_ENABLED | mocs_wb << 22 |
 128                 (2 * stencil_mt->pitch - 1));
 129       OUT_RELOC64(stencil_mt->bo,
 130                   I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
 131                   stencil_offset);
 132       OUT_BATCH(stencil_mt ? stencil_mt->qpitch >> 2 : 0);
 133       ADVANCE_BATCH();
 134    }
 135
 136    BEGIN_BATCH(3);
 137    OUT_BATCH(GEN7_3DSTATE_CLEAR_PARAMS << 16 | (3 - 2));
 138    OUT_BATCH(depth_mt ? depth_mt->depth_clear_value : 0);
 139    OUT_BATCH(1);
 140    ADVANCE_BATCH();
 141
 142    brw->no_depth_or_stencil = !depth_mt && !stencil_mt;
 143 }
 144
 145 /* Awful vtable-compatible function; should be cleaned up in the future. */
 146 void
 147 gen8_emit_depth_stencil_hiz(struct brw_context *brw,
 148                             struct intel_mipmap_tree *depth_mt,
 149                             uint32_t depth_offset,
 150                             uint32_t depthbuffer_format,
 151                             uint32_t depth_surface_type,
 152                             struct intel_mipmap_tree *stencil_mt,
 153                             bool hiz, bool separate_stencil,
 154                             uint32_t width, uint32_t height,
 155                             uint32_t tile_x, uint32_t tile_y)
 156 {
 157    struct gl_context *ctx = &brw->ctx;
 158    struct gl_framebuffer *fb = ctx->DrawBuffer;
 159    uint32_t surftype;
 160    unsigned int depth = 1;
 161    unsigned int min_array_element;
 162    GLenum gl_target = GL_TEXTURE_2D;
 163    unsigned int lod;
 164    const struct intel_mipmap_tree *mt = depth_mt ? depth_mt : stencil_mt;
 165    const struct intel_renderbuffer *irb = NULL;
 166    const struct gl_renderbuffer *rb = NULL;
 167
 168    irb = intel_get_renderbuffer(fb, BUFFER_DEPTH);
 169    if (!irb)
 170       irb = intel_get_renderbuffer(fb, BUFFER_STENCIL);
 171    rb = (struct gl_renderbuffer *) irb;
 172
 173    if (rb) {
 174       depth = MAX2(irb->layer_count, 1);
 175       if (rb->TexImage)
 176          gl_target = rb->TexImage->TexObject->Target;
 177    }
 178
 179    switch (gl_target) {
 180    case GL_TEXTURE_CUBE_MAP_ARRAY:
 181    case GL_TEXTURE_CUBE_MAP:
 182       /* The PRM claims that we should use BRW_SURFACE_CUBE for this
 183        * situation, but experiments show that gl_Layer doesn't work when we do
 184        * this.  So we use BRW_SURFACE_2D, since for rendering purposes this is
 185        * equivalent.
 186        */
 187       surftype = BRW_SURFACE_2D;
 188       depth *= 6;
 189       break;
 190    case GL_TEXTURE_3D:
 191       assert(mt);
 192       depth = MAX2(mt->logical_depth0, 1);
 193       surftype = translate_tex_target(gl_target);
 194       break;
 195    case GL_TEXTURE_1D_ARRAY:
 196    case GL_TEXTURE_1D:
 197       if (brw->gen >= 9) {
 198          /* WaDisable1DDepthStencil. Skylake+ doesn't support 1D depth
 199           * textures but it does allow pretending it's a 2D texture
 200           * instead.
 201           */
 202          surftype = BRW_SURFACE_2D;
 203          break;
 204       }
 205       /* fallthrough */
 206    default:
 207       surftype = translate_tex_target(gl_target);
 208       break;
 209    }
 210
 211    min_array_element = irb ? irb->mt_layer : 0;
 212
 213    lod = irb ? irb->mt_level - irb->mt->first_level : 0;
 214
 215    if (mt) {
 216       width = mt->logical_width0;
 217       height = mt->logical_height0;
 218    }
 219
 220    emit_depth_packets(brw, depth_mt, brw_depthbuffer_format(brw), surftype,
 221                       ctx->Depth.Mask != 0,
 222                       stencil_mt, ctx->Stencil._WriteEnabled,
 223                       brw->depthstencil.stencil_offset,
 224                       hiz, width, height, depth, lod, min_array_element);
 225 }
 226
 227 /**
 228  * Should we set the PMA FIX ENABLE bit?
 229  *
 230  * To avoid unnecessary depth related stalls, we need to set this bit.
 231  * However, there is a very complicated formula which governs when it
 232  * is legal to do so.  This function computes that.
 233  *
 234  * See the documenation for the CACHE_MODE_1 register, bit 11.
 235  */
 236 static bool
 237 pma_fix_enable(const struct brw_context *brw)
 238 {
 239    const struct gl_context *ctx = &brw->ctx;
 240    /* _NEW_BUFFERS */
 241    struct intel_renderbuffer *depth_irb =
 242       intel_get_renderbuffer(ctx->DrawBuffer, BUFFER_DEPTH);
 243
 244    /* 3DSTATE_WM::ForceThreadDispatch is never used. */
 245    const bool wm_force_thread_dispatch = false;
 246
 247    /* 3DSTATE_RASTER::ForceSampleCount is never used. */
 248    const bool raster_force_sample_count_nonzero = false;
 249
 250    /* _NEW_BUFFERS:
 251     * 3DSTATE_DEPTH_BUFFER::SURFACE_TYPE != NULL &&
 252     * 3DSTATE_DEPTH_BUFFER::HIZ Enable
 253     */
 254    const bool hiz_enabled = depth_irb && intel_renderbuffer_has_hiz(depth_irb);
 255
 256    /* 3DSTATE_WM::Early Depth/Stencil Control != EDSC_PREPS (2).
 257     * We always leave this set to EDSC_NORMAL (0).
 258     */
 259    const bool edsc_not_preps = true;
 260
 261    /* 3DSTATE_PS_EXTRA::PixelShaderValid is always true. */
 262    const bool pixel_shader_valid = true;
 263
 264    /* !(3DSTATE_WM_HZ_OP::DepthBufferClear ||
 265     *   3DSTATE_WM_HZ_OP::DepthBufferResolve ||
 266     *   3DSTATE_WM_HZ_OP::Hierarchical Depth Buffer Resolve Enable ||
 267     *   3DSTATE_WM_HZ_OP::StencilBufferClear)
 268     *
 269     * HiZ operations are done outside of the normal state upload, so they're
 270     * definitely not happening now.
 271     */
 272    const bool in_hiz_op = false;
 273
 274    /* _NEW_DEPTH:
 275     * DEPTH_STENCIL_STATE::DepthTestEnable
 276     */
 277    const bool depth_test_enabled = depth_irb && ctx->Depth.Test;
 278
 279    /* _NEW_DEPTH:
 280     * 3DSTATE_WM_DEPTH_STENCIL::DepthWriteEnable &&
 281     * 3DSTATE_DEPTH_BUFFER::DEPTH_WRITE_ENABLE.
 282     */
 283    const bool depth_writes_enabled = ctx->Depth.Mask;
 284
 285    /* _NEW_STENCIL:
 286     * !DEPTH_STENCIL_STATE::Stencil Buffer Write Enable ||
 287     * !3DSTATE_DEPTH_BUFFER::Stencil Buffer Enable ||
 288     * !3DSTATE_STENCIL_BUFFER::Stencil Buffer Enable
 289     */
 290    const bool stencil_writes_enabled = ctx->Stencil._WriteEnabled;
 291
 292    /* BRW_NEW_FS_PROG_DATA:
 293     * 3DSTATE_PS_EXTRA::Pixel Shader Computed Depth Mode != PSCDEPTH_OFF
 294     */
 295    const bool ps_computes_depth =
 296       brw->wm.prog_data->computed_depth_mode != BRW_PSCDEPTH_OFF;
 297
 298    /* BRW_NEW_FS_PROG_DATA:        3DSTATE_PS_EXTRA::PixelShaderKillsPixels
 299     * BRW_NEW_FS_PROG_DATA:        3DSTATE_PS_EXTRA::oMask Present to RenderTarget
 300     * _NEW_MULTISAMPLE:         3DSTATE_PS_BLEND::AlphaToCoverageEnable
 301     * _NEW_COLOR:               3DSTATE_PS_BLEND::AlphaTestEnable
 302     *
 303     * 3DSTATE_WM_CHROMAKEY::ChromaKeyKillEnable is always false.
 304     * 3DSTATE_WM::ForceKillPix != ForceOff is always true.
 305     */
 306    const bool kill_pixel =
 307       brw->wm.prog_data->uses_kill ||
 308       brw->wm.prog_data->uses_omask ||
 309       (ctx->Multisample._Enabled && ctx->Multisample.SampleAlphaToCoverage) ||
 310       ctx->Color.AlphaEnabled;
 311
 312    /* The big formula in CACHE_MODE_1::NP PMA FIX ENABLE. */
 313    return !wm_force_thread_dispatch &&
 314           !raster_force_sample_count_nonzero &&
 315           hiz_enabled &&
 316           edsc_not_preps &&
 317           pixel_shader_valid &&
 318           !in_hiz_op &&
 319           depth_test_enabled &&
 320           (ps_computes_depth ||
 321            (kill_pixel && (depth_writes_enabled || stencil_writes_enabled)));
 322 }
 323
 324 static void
 325 write_pma_stall_bits(struct brw_context *brw, uint32_t pma_stall_bits)
 326 {
 327    struct gl_context *ctx = &brw->ctx;
 328
 329    /* If we haven't actually changed the value, bail now to avoid unnecessary
 330     * pipeline stalls and register writes.
 331     */
 332    if (brw->pma_stall_bits == pma_stall_bits)
 333       return;
 334
 335    brw->pma_stall_bits = pma_stall_bits;
 336
 337    /* According to the PIPE_CONTROL documentation, software should emit a
 338     * PIPE_CONTROL with the CS Stall and Depth Cache Flush bits set prior
 339     * to the LRI.  If stencil buffer writes are enabled, then a Render Cache
 340     * Flush is also necessary.
 341     */
 342    const uint32_t render_cache_flush =
 343       ctx->Stencil._WriteEnabled ? PIPE_CONTROL_RENDER_TARGET_FLUSH : 0;
 344    brw_emit_pipe_control_flush(brw,
 345                                PIPE_CONTROL_CS_STALL |
 346                                PIPE_CONTROL_DEPTH_CACHE_FLUSH |
 347                                render_cache_flush);
 348
 349    /* CACHE_MODE_1 is a non-privileged register. */
 350    BEGIN_BATCH(3);
 351    OUT_BATCH(MI_LOAD_REGISTER_IMM | (3 - 2));
 352    OUT_BATCH(GEN7_CACHE_MODE_1);
 353    OUT_BATCH(GEN8_HIZ_PMA_MASK_BITS | pma_stall_bits);
 354    ADVANCE_BATCH();
 355
 356    /* After the LRI, a PIPE_CONTROL with both the Depth Stall and Depth Cache
 357     * Flush bits is often necessary.  We do it regardless because it's easier.
 358     * The render cache flush is also necessary if stencil writes are enabled.
 359     */
 360    brw_emit_pipe_control_flush(brw,
 361                                PIPE_CONTROL_DEPTH_STALL |
 362                                PIPE_CONTROL_DEPTH_CACHE_FLUSH |
 363                                render_cache_flush);
 364
 365 }
 366
 367 static void
 368 gen8_emit_pma_stall_workaround(struct brw_context *brw)
 369 {
 370    uint32_t bits = 0;
 371
 372    if (brw->gen >= 9)
 373       return;
 374
 375    if (pma_fix_enable(brw))
 376       bits |= GEN8_HIZ_NP_PMA_FIX_ENABLE | GEN8_HIZ_NP_EARLY_Z_FAILS_DISABLE;
 377
 378    write_pma_stall_bits(brw, bits);
 379 }
 380
 381 const struct brw_tracked_state gen8_pma_fix = {
 382    .dirty = {
 383       .mesa = _NEW_BUFFERS |
 384               _NEW_COLOR |
 385               _NEW_DEPTH |
 386               _NEW_MULTISAMPLE |
 387               _NEW_STENCIL,
 388       .brw = BRW_NEW_FS_PROG_DATA,
 389    },
 390    .emit = gen8_emit_pma_stall_workaround
 391 };
 392
 393 /**
 394  * Emit packets to perform a depth/HiZ resolve or fast depth/stencil clear.
 395  *
 396  * See the "Optimized Depth Buffer Clear and/or Stencil Buffer Clear" section
 397  * of the hardware documentation for details.
 398  */
 399 void
 400 gen8_hiz_exec(struct brw_context *brw, struct intel_mipmap_tree *mt,
 401               unsigned int level, unsigned int layer, enum gen6_hiz_op op)
 402 {
 403    if (op == GEN6_HIZ_OP_NONE)
 404       return;
 405
 406    /* Disable the PMA stall fix since we're about to do a HiZ operation. */
 407    if (brw->gen == 8)
 408       write_pma_stall_bits(brw, 0);
 409
 410    assert(mt->first_level == 0);
 411    assert(mt->logical_depth0 >= 1);
 412
 413    /* If we're operating on LOD 0, align to 8x4 to meet the alignment
 414     * requirements for most HiZ operations.  Otherwise, use the actual size
 415     * to allow the hardware to calculate the miplevel offsets correctly.
 416     */
 417    uint32_t surface_width  = ALIGN(mt->logical_width0,  level == 0 ? 8 : 1);
 418    uint32_t surface_height = ALIGN(mt->logical_height0, level == 0 ? 4 : 1);
 419
 420    /* The basic algorithm is:
 421     * - If needed, emit 3DSTATE_{DEPTH,HIER_DEPTH,STENCIL}_BUFFER and
 422     *   3DSTATE_CLEAR_PARAMS packets to set up the relevant buffers.
 423     * - If needed, emit 3DSTATE_DRAWING_RECTANGLE.
 424     * - Emit 3DSTATE_WM_HZ_OP with a bit set for the particular operation.
 425     * - Do a special PIPE_CONTROL to trigger an implicit rectangle primitive.
 426     * - Emit 3DSTATE_WM_HZ_OP with no bits set to return to normal rendering.
 427     */
 428    emit_depth_packets(brw, mt,
 429                       brw_depth_format(brw, mt->format),
 430                       BRW_SURFACE_2D,
 431                       true, /* depth writes */
 432                       NULL, false, 0, /* no stencil for now */
 433                       true, /* hiz */
 434                       surface_width,
 435                       surface_height,
 436                       mt->logical_depth0,
 437                       level,
 438                       layer); /* min_array_element */
 439
 440    /* Depth buffer clears and HiZ resolves must use an 8x4 aligned rectangle.
 441     * Note that intel_miptree_level_enable_hiz disables HiZ for miplevels > 0
 442     * which aren't 8x4 aligned, so expanding the size is safe - it'll just
 443     * draw into empty padding space.
 444     */
 445    unsigned rect_width = ALIGN(minify(mt->logical_width0, level), 8);
 446    unsigned rect_height = ALIGN(minify(mt->logical_height0, level), 4);
 447
 448    BEGIN_BATCH(4);
 449    OUT_BATCH(_3DSTATE_DRAWING_RECTANGLE << 16 | (4 - 2));
 450    OUT_BATCH(0);
 451    OUT_BATCH(((rect_width - 1) & 0xffff) | ((rect_height - 1) << 16));
 452    OUT_BATCH(0);
 453    ADVANCE_BATCH();
 454
 455    /* Emit 3DSTATE_WM_HZ_OP to override pipeline state for the particular
 456     * resolve or clear operation we want to perform.
 457     */
 458    uint32_t dw1 = 0;
 459
 460    switch (op) {
 461    case GEN6_HIZ_OP_DEPTH_RESOLVE:
 462       dw1 |= GEN8_WM_HZ_DEPTH_RESOLVE;
 463       break;
 464    case GEN6_HIZ_OP_HIZ_RESOLVE:
 465       dw1 |= GEN8_WM_HZ_HIZ_RESOLVE;
 466       break;
 467    case GEN6_HIZ_OP_DEPTH_CLEAR:
 468       dw1 |= GEN8_WM_HZ_DEPTH_CLEAR;
 469       break;
 470    case GEN6_HIZ_OP_NONE:
 471       unreachable("Should not get here.");
 472    }
 473
 474    if (mt->num_samples > 0)
 475       dw1 |= SET_FIELD(ffs(mt->num_samples) - 1, GEN8_WM_HZ_NUM_SAMPLES);
 476
 477    BEGIN_BATCH(5);
 478    OUT_BATCH(_3DSTATE_WM_HZ_OP << 16 | (5 - 2));
 479    OUT_BATCH(dw1);
 480    OUT_BATCH(0);
 481    OUT_BATCH(SET_FIELD(rect_width, GEN8_WM_HZ_CLEAR_RECTANGLE_X_MAX) |
 482              SET_FIELD(rect_height, GEN8_WM_HZ_CLEAR_RECTANGLE_Y_MAX));
 483    OUT_BATCH(SET_FIELD(0xFFFF, GEN8_WM_HZ_SAMPLE_MASK));
 484    ADVANCE_BATCH();
 485
 486    /* Emit a PIPE_CONTROL with "Post-Sync Operation" set to "Write Immediate
 487     * Data", and no other bits set.  This causes 3DSTATE_WM_HZ_OP's state to
 488     * take effect, and spawns a rectangle primitive.
 489     */
 490    brw_emit_pipe_control_write(brw,
 491                                PIPE_CONTROL_WRITE_IMMEDIATE,
 492                                brw->batch.workaround_bo, 0, 0, 0);
 493
 494    /* Emit 3DSTATE_WM_HZ_OP again to disable the state overrides. */
 495    BEGIN_BATCH(5);
 496    OUT_BATCH(_3DSTATE_WM_HZ_OP << 16 | (5 - 2));
 497    OUT_BATCH(0);
 498    OUT_BATCH(0);
 499    OUT_BATCH(0);
 500    OUT_BATCH(0);
 501    ADVANCE_BATCH();
 502
 503    /* Mark this buffer as needing a TC flush, as we've rendered to it. */
 504    brw_render_cache_set_add_bo(brw, mt->bo);
 505
 506    /* We've clobbered all of the depth packets, and the drawing rectangle,
 507     * so we need to ensure those packets are re-emitted before the next
 508     * primitive.
 509     *
 510     * Setting _NEW_DEPTH and _NEW_BUFFERS covers it, but is rather overkill.
 511     */
 512    brw->NewGLState |= _NEW_DEPTH | _NEW_BUFFERS;
 513 }