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

   1 /**************************************************************************
   2  *
   3  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include <sys/errno.h>
  29
  30 #include "main/glheader.h"
  31 #include "main/context.h"
  32 #include "main/condrender.h"
  33 #include "main/samplerobj.h"
  34 #include "main/state.h"
  35 #include "main/enums.h"
  36 #include "main/macros.h"
  37 #include "tnl/tnl.h"
  38 #include "vbo/vbo_context.h"
  39 #include "swrast/swrast.h"
  40 #include "swrast_setup/swrast_setup.h"
  41 #include "drivers/common/meta.h"
  42
  43 #include "brw_draw.h"
  44 #include "brw_defines.h"
  45 #include "brw_context.h"
  46 #include "brw_state.h"
  47
  48 #include "intel_batchbuffer.h"
  49 #include "intel_fbo.h"
  50 #include "intel_mipmap_tree.h"
  51 #include "intel_regions.h"
  52
  53 #define FILE_DEBUG_FLAG DEBUG_PRIMS
  54
  55 static GLuint prim_to_hw_prim[GL_POLYGON+1] = {
  56    _3DPRIM_POINTLIST,
  57    _3DPRIM_LINELIST,
  58    _3DPRIM_LINELOOP,
  59    _3DPRIM_LINESTRIP,
  60    _3DPRIM_TRILIST,
  61    _3DPRIM_TRISTRIP,
  62    _3DPRIM_TRIFAN,
  63    _3DPRIM_QUADLIST,
  64    _3DPRIM_QUADSTRIP,
  65    _3DPRIM_POLYGON
  66 };
  67
  68
  69 static const GLenum reduced_prim[GL_POLYGON+1] = {
  70    GL_POINTS,
  71    GL_LINES,
  72    GL_LINES,
  73    GL_LINES,
  74    GL_TRIANGLES,
  75    GL_TRIANGLES,
  76    GL_TRIANGLES,
  77    GL_TRIANGLES,
  78    GL_TRIANGLES,
  79    GL_TRIANGLES
  80 };
  81
  82
  83 /* When the primitive changes, set a state bit and re-validate.  Not
  84  * the nicest and would rather deal with this by having all the
  85  * programs be immune to the active primitive (ie. cope with all
  86  * possibilities).  That may not be realistic however.
  87  */
  88 static void brw_set_prim(struct brw_context *brw,
  89                          const struct _mesa_prim *prim)
  90 {
  91    struct gl_context *ctx = &brw->intel.ctx;
  92    uint32_t hw_prim = prim_to_hw_prim[prim->mode];
  93
  94    DBG("PRIM: %s\n", _mesa_lookup_enum_by_nr(prim->mode));
  95
  96    /* Slight optimization to avoid the GS program when not needed:
  97     */
  98    if (prim->mode == GL_QUAD_STRIP &&
  99        ctx->Light.ShadeModel != GL_FLAT &&
 100        ctx->Polygon.FrontMode == GL_FILL &&
 101        ctx->Polygon.BackMode == GL_FILL)
 102       hw_prim = _3DPRIM_TRISTRIP;
 103
 104    if (prim->mode == GL_QUADS && prim->count == 4 &&
 105        ctx->Light.ShadeModel != GL_FLAT &&
 106        ctx->Polygon.FrontMode == GL_FILL &&
 107        ctx->Polygon.BackMode == GL_FILL) {
 108       hw_prim = _3DPRIM_TRIFAN;
 109    }
 110
 111    if (hw_prim != brw->primitive) {
 112       brw->primitive = hw_prim;
 113       brw->state.dirty.brw |= BRW_NEW_PRIMITIVE;
 114
 115       if (reduced_prim[prim->mode] != brw->intel.reduced_primitive) {
 116          brw->intel.reduced_primitive = reduced_prim[prim->mode];
 117          brw->state.dirty.brw |= BRW_NEW_REDUCED_PRIMITIVE;
 118       }
 119    }
 120 }
 121
 122 static void gen6_set_prim(struct brw_context *brw,
 123                           const struct _mesa_prim *prim)
 124 {
 125    uint32_t hw_prim;
 126
 127    DBG("PRIM: %s\n", _mesa_lookup_enum_by_nr(prim->mode));
 128
 129    hw_prim = prim_to_hw_prim[prim->mode];
 130
 131    if (hw_prim != brw->primitive) {
 132       brw->primitive = hw_prim;
 133       brw->state.dirty.brw |= BRW_NEW_PRIMITIVE;
 134    }
 135 }
 136
 137
 138 static GLuint trim(GLenum prim, GLuint length)
 139 {
 140    if (prim == GL_QUAD_STRIP)
 141       return length > 3 ? (length - length % 2) : 0;
 142    else if (prim == GL_QUADS)
 143       return length - length % 4;
 144    else
 145       return length;
 146 }
 147
 148
 149 static void brw_emit_prim(struct brw_context *brw,
 150                           const struct _mesa_prim *prim,
 151                           uint32_t hw_prim)
 152 {
 153    struct intel_context *intel = &brw->intel;
 154    int verts_per_instance;
 155    int vertex_access_type;
 156    int start_vertex_location;
 157    int base_vertex_location;
 158
 159    DBG("PRIM: %s %d %d\n", _mesa_lookup_enum_by_nr(prim->mode),
 160        prim->start, prim->count);
 161
 162    start_vertex_location = prim->start;
 163    base_vertex_location = prim->basevertex;
 164    if (prim->indexed) {
 165       vertex_access_type = GEN4_3DPRIM_VERTEXBUFFER_ACCESS_RANDOM;
 166       start_vertex_location += brw->ib.start_vertex_offset;
 167       base_vertex_location += brw->vb.start_vertex_bias;
 168    } else {
 169       vertex_access_type = GEN4_3DPRIM_VERTEXBUFFER_ACCESS_SEQUENTIAL;
 170       start_vertex_location += brw->vb.start_vertex_bias;
 171    }
 172
 173    verts_per_instance = trim(prim->mode, prim->count);
 174
 175    /* If nothing to emit, just return. */
 176    if (verts_per_instance == 0)
 177       return;
 178
 179    /* If we're set to always flush, do it before and after the primitive emit.
 180     * We want to catch both missed flushes that hurt instruction/state cache
 181     * and missed flushes of the render cache as it heads to other parts of
 182     * the besides the draw code.
 183     */
 184    if (intel->always_flush_cache) {
 185       intel_batchbuffer_emit_mi_flush(intel);
 186    }
 187
 188    BEGIN_BATCH(6);
 189    OUT_BATCH(CMD_3D_PRIM << 16 | (6 - 2) |
 190              hw_prim << GEN4_3DPRIM_TOPOLOGY_TYPE_SHIFT |
 191              vertex_access_type);
 192    OUT_BATCH(verts_per_instance);
 193    OUT_BATCH(start_vertex_location);
 194    OUT_BATCH(prim->num_instances);
 195    OUT_BATCH(0); // start instance location
 196    OUT_BATCH(base_vertex_location);
 197    ADVANCE_BATCH();
 198
 199    intel->batch.need_workaround_flush = true;
 200
 201    if (intel->always_flush_cache) {
 202       intel_batchbuffer_emit_mi_flush(intel);
 203    }
 204 }
 205
 206 static void gen7_emit_prim(struct brw_context *brw,
 207                            const struct _mesa_prim *prim,
 208                            uint32_t hw_prim)
 209 {
 210    struct intel_context *intel = &brw->intel;
 211    int verts_per_instance;
 212    int vertex_access_type;
 213    int start_vertex_location;
 214    int base_vertex_location;
 215
 216    DBG("PRIM: %s %d %d\n", _mesa_lookup_enum_by_nr(prim->mode),
 217        prim->start, prim->count);
 218
 219    start_vertex_location = prim->start;
 220    base_vertex_location = prim->basevertex;
 221    if (prim->indexed) {
 222       vertex_access_type = GEN7_3DPRIM_VERTEXBUFFER_ACCESS_RANDOM;
 223       start_vertex_location += brw->ib.start_vertex_offset;
 224       base_vertex_location += brw->vb.start_vertex_bias;
 225    } else {
 226       vertex_access_type = GEN7_3DPRIM_VERTEXBUFFER_ACCESS_SEQUENTIAL;
 227       start_vertex_location += brw->vb.start_vertex_bias;
 228    }
 229
 230    verts_per_instance = trim(prim->mode, prim->count);
 231
 232    /* If nothing to emit, just return. */
 233    if (verts_per_instance == 0)
 234       return;
 235
 236    /* If we're set to always flush, do it before and after the primitive emit.
 237     * We want to catch both missed flushes that hurt instruction/state cache
 238     * and missed flushes of the render cache as it heads to other parts of
 239     * the besides the draw code.
 240     */
 241    if (intel->always_flush_cache) {
 242       intel_batchbuffer_emit_mi_flush(intel);
 243    }
 244
 245    BEGIN_BATCH(7);
 246    OUT_BATCH(CMD_3D_PRIM << 16 | (7 - 2));
 247    OUT_BATCH(hw_prim | vertex_access_type);
 248    OUT_BATCH(verts_per_instance);
 249    OUT_BATCH(start_vertex_location);
 250    OUT_BATCH(prim->num_instances);
 251    OUT_BATCH(0); // start instance location
 252    OUT_BATCH(base_vertex_location);
 253    ADVANCE_BATCH();
 254
 255    if (intel->always_flush_cache) {
 256       intel_batchbuffer_emit_mi_flush(intel);
 257    }
 258 }
 259
 260
 261 static void brw_merge_inputs( struct brw_context *brw,
 262                        const struct gl_client_array *arrays[])
 263 {
 264    struct brw_vertex_info old = brw->vb.info;
 265    GLuint i;
 266
 267    for (i = 0; i < brw->vb.nr_buffers; i++) {
 268       drm_intel_bo_unreference(brw->vb.buffers[i].bo);
 269       brw->vb.buffers[i].bo = NULL;
 270    }
 271    brw->vb.nr_buffers = 0;
 272
 273    memset(&brw->vb.info, 0, sizeof(brw->vb.info));
 274
 275    for (i = 0; i < VERT_ATTRIB_MAX; i++) {
 276       brw->vb.inputs[i].buffer = -1;
 277       brw->vb.inputs[i].glarray = arrays[i];
 278       brw->vb.inputs[i].attrib = (gl_vert_attrib) i;
 279
 280       if (arrays[i]->StrideB != 0)
 281          brw->vb.info.sizes[i/16] |= (brw->vb.inputs[i].glarray->Size - 1) <<
 282             ((i%16) * 2);
 283    }
 284
 285    /* Raise statechanges if input sizes have changed. */
 286    if (memcmp(brw->vb.info.sizes, old.sizes, sizeof(old.sizes)) != 0)
 287       brw->state.dirty.brw |= BRW_NEW_INPUT_DIMENSIONS;
 288 }
 289
 290 /*
 291  * \brief Resolve buffers before drawing.
 292  *
 293  * Resolve the depth buffer's HiZ buffer and resolve the depth buffer of each
 294  * enabled depth texture.
 295  *
 296  * (In the future, this will also perform MSAA resolves).
 297  */
 298 static void
 299 brw_predraw_resolve_buffers(struct brw_context *brw)
 300 {
 301    struct gl_context *ctx = &brw->intel.ctx;
 302    struct intel_context *intel = &brw->intel;
 303    struct intel_renderbuffer *depth_irb;
 304    struct intel_texture_object *tex_obj;
 305
 306    /* Resolve the depth buffer's HiZ buffer. */
 307    depth_irb = intel_get_renderbuffer(ctx->DrawBuffer, BUFFER_DEPTH);
 308    if (depth_irb && depth_irb->mt) {
 309       intel_renderbuffer_resolve_hiz(intel, depth_irb);
 310    }
 311
 312    /* Resolve depth buffer of each enabled depth texture. */
 313    for (int i = 0; i < BRW_MAX_TEX_UNIT; i++) {
 314       if (!ctx->Texture.Unit[i]._ReallyEnabled)
 315          continue;
 316       tex_obj = intel_texture_object(ctx->Texture.Unit[i]._Current);
 317       if (!tex_obj || !tex_obj->mt)
 318          continue;
 319       intel_miptree_all_slices_resolve_depth(intel, tex_obj->mt);
 320    }
 321 }
 322
 323 /**
 324  * \brief Call this after drawing to mark which buffers need resolving
 325  *
 326  * If the depth buffer was written to and if it has an accompanying HiZ
 327  * buffer, then mark that it needs a depth resolve.
 328  *
 329  * (In the future, this will also mark needed MSAA resolves).
 330  */
 331 static void brw_postdraw_set_buffers_need_resolve(struct brw_context *brw)
 332 {
 333    struct gl_context *ctx = &brw->intel.ctx;
 334    struct gl_framebuffer *fb = ctx->DrawBuffer;
 335    struct intel_renderbuffer *depth_irb =
 336          intel_get_renderbuffer(fb, BUFFER_DEPTH);
 337
 338    if (depth_irb && ctx->Depth.Mask) {
 339       intel_renderbuffer_set_needs_depth_resolve(depth_irb);
 340    }
 341 }
 342
 343 static int
 344 verts_per_prim(GLenum mode)
 345 {
 346    switch (mode) {
 347    case GL_POINTS:
 348       return 1;
 349    case GL_LINE_STRIP:
 350    case GL_LINE_LOOP:
 351    case GL_LINES:
 352       return 2;
 353    case GL_TRIANGLE_STRIP:
 354    case GL_TRIANGLE_FAN:
 355    case GL_POLYGON:
 356    case GL_TRIANGLES:
 357    case GL_QUADS:
 358    case GL_QUAD_STRIP:
 359       return 3;
 360    default:
 361       _mesa_problem(NULL,
 362                     "unknown prim type in transform feedback primitive count");
 363       return 0;
 364    }
 365 }
 366
 367 /**
 368  * Update internal counters based on the the drawing operation described in
 369  * prim.
 370  */
 371 static void
 372 brw_update_primitive_count(struct brw_context *brw,
 373                            const struct _mesa_prim *prim)
 374 {
 375    uint32_t count = count_tessellated_primitives(prim);
 376    brw->sol.primitives_generated += count;
 377    if (brw->intel.ctx.TransformFeedback.CurrentObject->Active &&
 378        !brw->intel.ctx.TransformFeedback.CurrentObject->Paused) {
 379       /* Update brw->sol.svbi_0_max_index to reflect the amount by which the
 380        * hardware is going to increment SVBI 0 when this drawing operation
 381        * occurs.  This is necessary because the kernel does not (yet) save and
 382        * restore GPU registers when context switching, so we'll need to be
 383        * able to reload SVBI 0 with the correct value in case we have to start
 384        * a new batch buffer.
 385        */
 386       unsigned verts = verts_per_prim(prim->mode);
 387       uint32_t space_avail =
 388          (brw->sol.svbi_0_max_index - brw->sol.svbi_0_starting_index) / verts;
 389       uint32_t primitives_written = MIN2 (space_avail, count);
 390       brw->sol.svbi_0_starting_index += verts * primitives_written;
 391
 392       /* And update the TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN query. */
 393       brw->sol.primitives_written += primitives_written;
 394    }
 395 }
 396
 397 /* May fail if out of video memory for texture or vbo upload, or on
 398  * fallback conditions.
 399  */
 400 static bool brw_try_draw_prims( struct gl_context *ctx,
 401                                      const struct gl_client_array *arrays[],
 402                                      const struct _mesa_prim *prim,
 403                                      GLuint nr_prims,
 404                                      const struct _mesa_index_buffer *ib,
 405                                      GLuint min_index,
 406                                      GLuint max_index )
 407 {
 408    struct intel_context *intel = intel_context(ctx);
 409    struct brw_context *brw = brw_context(ctx);
 410    bool retval = true;
 411    GLuint i;
 412    bool fail_next = false;
 413
 414    if (ctx->NewState)
 415       _mesa_update_state( ctx );
 416
 417    /* We have to validate the textures *before* checking for fallbacks;
 418     * otherwise, the software fallback won't be able to rely on the
 419     * texture state, the firstLevel and lastLevel fields won't be
 420     * set in the intel texture object (they'll both be 0), and the
 421     * software fallback will segfault if it attempts to access any
 422     * texture level other than level 0.
 423     */
 424    brw_validate_textures( brw );
 425
 426    /* Resolves must occur after updating state and finalizing textures but
 427     * before setting up any hardware state for this draw call.
 428     */
 429    brw_predraw_resolve_buffers(brw);
 430
 431    /* Bind all inputs, derive varying and size information:
 432     */
 433    brw_merge_inputs( brw, arrays );
 434
 435    brw->ib.ib = ib;
 436    brw->state.dirty.brw |= BRW_NEW_INDICES;
 437
 438    brw->vb.min_index = min_index;
 439    brw->vb.max_index = max_index;
 440    brw->state.dirty.brw |= BRW_NEW_VERTICES;
 441
 442    /* Have to validate state quite late.  Will rebuild tnl_program,
 443     * which depends on varying information.
 444     *
 445     * Note this is where brw->vs->prog_data.inputs_read is calculated,
 446     * so can't access it earlier.
 447     */
 448
 449    intel_prepare_render(intel);
 450
 451    for (i = 0; i < nr_prims; i++) {
 452       int estimated_max_prim_size;
 453
 454       estimated_max_prim_size = 512; /* batchbuffer commands */
 455       estimated_max_prim_size += (BRW_MAX_TEX_UNIT *
 456                                   (sizeof(struct brw_sampler_state) +
 457                                    sizeof(struct gen5_sampler_default_color)));
 458       estimated_max_prim_size += 1024; /* gen6 VS push constants */
 459       estimated_max_prim_size += 1024; /* gen6 WM push constants */
 460       estimated_max_prim_size += 512; /* misc. pad */
 461
 462       /* Flush the batch if it's approaching full, so that we don't wrap while
 463        * we've got validated state that needs to be in the same batch as the
 464        * primitives.
 465        */
 466       intel_batchbuffer_require_space(intel, estimated_max_prim_size, false);
 467       intel_batchbuffer_save_state(intel);
 468
 469       brw->num_instances = prim->num_instances;
 470       if (intel->gen < 6)
 471          brw_set_prim(brw, &prim[i]);
 472       else
 473          gen6_set_prim(brw, &prim[i]);
 474
 475 retry:
 476       /* Note that before the loop, brw->state.dirty.brw was set to != 0, and
 477        * that the state updated in the loop outside of this block is that in
 478        * *_set_prim or intel_batchbuffer_flush(), which only impacts
 479        * brw->state.dirty.brw.
 480        */
 481       if (brw->state.dirty.brw) {
 482          intel->no_batch_wrap = true;
 483          brw_upload_state(brw);
 484
 485          if (unlikely(brw->intel.Fallback)) {
 486             intel->no_batch_wrap = false;
 487             retval = false;
 488             goto out;
 489          }
 490       }
 491
 492       if (intel->gen >= 7)
 493          gen7_emit_prim(brw, &prim[i], brw->primitive);
 494       else
 495          brw_emit_prim(brw, &prim[i], brw->primitive);
 496
 497       intel->no_batch_wrap = false;
 498
 499       if (dri_bufmgr_check_aperture_space(&intel->batch.bo, 1)) {
 500          if (!fail_next) {
 501             intel_batchbuffer_reset_to_saved(intel);
 502             intel_batchbuffer_flush(intel);
 503             fail_next = true;
 504             goto retry;
 505          } else {
 506             if (intel_batchbuffer_flush(intel) == -ENOSPC) {
 507                static bool warned = false;
 508
 509                if (!warned) {
 510                   fprintf(stderr, "i965: Single primitive emit exceeded"
 511                           "available aperture space\n");
 512                   warned = true;
 513                }
 514
 515                retval = false;
 516             }
 517          }
 518       }
 519
 520       if (!_mesa_meta_in_progress(ctx))
 521          brw_update_primitive_count(brw, &prim[i]);
 522    }
 523
 524    if (intel->always_flush_batch)
 525       intel_batchbuffer_flush(intel);
 526  out:
 527
 528    brw_state_cache_check_size(brw);
 529    brw_postdraw_set_buffers_need_resolve(brw);
 530
 531    return retval;
 532 }
 533
 534 void brw_draw_prims( struct gl_context *ctx,
 535                      const struct _mesa_prim *prim,
 536                      GLuint nr_prims,
 537                      const struct _mesa_index_buffer *ib,
 538                      GLboolean index_bounds_valid,
 539                      GLuint min_index,
 540                      GLuint max_index,
 541                      struct gl_transform_feedback_object *tfb_vertcount )
 542 {
 543    const struct gl_client_array **arrays = ctx->Array._DrawArrays;
 544    bool retval;
 545
 546    if (!_mesa_check_conditional_render(ctx))
 547       return;
 548
 549    /* Handle primitive restart if needed */
 550    if (brw_handle_primitive_restart(ctx, prim, nr_prims, ib)) {
 551       /* The draw was handled, so we can exit now */
 552       return;
 553    }
 554
 555    if (!vbo_all_varyings_in_vbos(arrays)) {
 556       if (!index_bounds_valid)
 557          vbo_get_minmax_indices(ctx, prim, ib, &min_index, &max_index, nr_prims);
 558
 559       /* Decide if we want to rebase.  If so we end up recursing once
 560        * only into this function.
 561        */
 562       if (min_index != 0 && !vbo_any_varyings_in_vbos(arrays)) {
 563          vbo_rebase_prims(ctx, arrays,
 564                           prim, nr_prims,
 565                           ib, min_index, max_index,
 566                           brw_draw_prims );
 567          return;
 568       }
 569    }
 570
 571    /* Make a first attempt at drawing:
 572     */
 573    retval = brw_try_draw_prims(ctx, arrays, prim, nr_prims, ib, min_index, max_index);
 574
 575    /* Otherwise, we really are out of memory.  Pass the drawing
 576     * command to the software tnl module and which will in turn call
 577     * swrast to do the drawing.
 578     */
 579    if (!retval) {
 580        _swsetup_Wakeup(ctx);
 581        _tnl_wakeup(ctx);
 582       _tnl_draw_prims(ctx, arrays, prim, nr_prims, ib, min_index, max_index);
 583    }
 584
 585 }
 586
 587 void brw_draw_init( struct brw_context *brw )
 588 {
 589    struct gl_context *ctx = &brw->intel.ctx;
 590    struct vbo_context *vbo = vbo_context(ctx);
 591    int i;
 592
 593    /* Register our drawing function:
 594     */
 595    vbo->draw_prims = brw_draw_prims;
 596
 597    for (i = 0; i < VERT_ATTRIB_MAX; i++)
 598       brw->vb.inputs[i].buffer = -1;
 599    brw->vb.nr_buffers = 0;
 600    brw->vb.nr_enabled = 0;
 601 }
 602
 603 void brw_draw_destroy( struct brw_context *brw )
 604 {
 605    int i;
 606
 607    for (i = 0; i < brw->vb.nr_buffers; i++) {
 608       drm_intel_bo_unreference(brw->vb.buffers[i].bo);
 609       brw->vb.buffers[i].bo = NULL;
 610    }
 611    brw->vb.nr_buffers = 0;
 612
 613    for (i = 0; i < brw->vb.nr_enabled; i++) {
 614       brw->vb.enabled[i]->buffer = -1;
 615    }
 616    brw->vb.nr_enabled = 0;
 617
 618    drm_intel_bo_unreference(brw->ib.bo);
 619    brw->ib.bo = NULL;
 620 }