#include "intel_batchbuffer.h"
#include "intel_mipmap_tree.h"
-#include "intel_regions.h"
#include "intel_fbo.h"
+#include "intel_resolve_map.h"
#include "brw_context.h"
#include "brw_state.h"
#include "brw_defines.h"
+#include "brw_wm.h"
+/**
+ * Helper function to emit depth related command packets.
+ */
+static void
+emit_depth_packets(struct brw_context *brw,
+ struct intel_mipmap_tree *depth_mt,
+ uint32_t depthbuffer_format,
+ uint32_t depth_surface_type,
+ bool depth_writable,
+ struct intel_mipmap_tree *stencil_mt,
+ bool stencil_writable,
+ bool hiz,
+ uint32_t width,
+ uint32_t height,
+ uint32_t depth,
+ uint32_t lod,
+ uint32_t min_array_element)
+{
+ uint32_t mocs_wb = brw->gen >= 9 ? SKL_MOCS_WB : BDW_MOCS_WB;
+
+ /* Skip repeated NULL depth/stencil emits (think 2D rendering). */
+ if (!depth_mt && !stencil_mt && brw->no_depth_or_stencil) {
+ assert(brw->hw_ctx);
+ return;
+ }
+
+ brw_emit_depth_stall_flushes(brw);
+
+ /* _NEW_BUFFERS, _NEW_DEPTH, _NEW_STENCIL */
+ BEGIN_BATCH(8);
+ OUT_BATCH(GEN7_3DSTATE_DEPTH_BUFFER << 16 | (8 - 2));
+ OUT_BATCH(depth_surface_type << 29 |
+ (depth_writable ? (1 << 28) : 0) |
+ (stencil_mt != NULL && stencil_writable) << 27 |
+ (hiz ? 1 : 0) << 22 |
+ depthbuffer_format << 18 |
+ (depth_mt ? depth_mt->pitch - 1 : 0));
+ if (depth_mt) {
+ OUT_RELOC64(depth_mt->bo,
+ I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER, 0);
+ } else {
+ OUT_BATCH(0);
+ OUT_BATCH(0);
+ }
+ OUT_BATCH(((width - 1) << 4) | ((height - 1) << 18) | lod);
+ OUT_BATCH(((depth - 1) << 21) | (min_array_element << 10) | mocs_wb);
+ OUT_BATCH(0);
+ OUT_BATCH(((depth - 1) << 21) | (depth_mt ? depth_mt->qpitch >> 2 : 0));
+ ADVANCE_BATCH();
+
+ if (!hiz) {
+ BEGIN_BATCH(5);
+ OUT_BATCH(GEN7_3DSTATE_HIER_DEPTH_BUFFER << 16 | (5 - 2));
+ OUT_BATCH(0);
+ OUT_BATCH(0);
+ OUT_BATCH(0);
+ OUT_BATCH(0);
+ ADVANCE_BATCH();
+ } else {
+ BEGIN_BATCH(5);
+ OUT_BATCH(GEN7_3DSTATE_HIER_DEPTH_BUFFER << 16 | (5 - 2));
+ OUT_BATCH((depth_mt->hiz_buf->pitch - 1) | mocs_wb << 25);
+ OUT_RELOC64(depth_mt->hiz_buf->bo,
+ I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER, 0);
+ OUT_BATCH(depth_mt->hiz_buf->qpitch >> 2);
+ ADVANCE_BATCH();
+ }
+
+ if (stencil_mt == NULL) {
+ BEGIN_BATCH(5);
+ OUT_BATCH(GEN7_3DSTATE_STENCIL_BUFFER << 16 | (5 - 2));
+ OUT_BATCH(0);
+ OUT_BATCH(0);
+ OUT_BATCH(0);
+ OUT_BATCH(0);
+ ADVANCE_BATCH();
+ } else {
+ BEGIN_BATCH(5);
+ OUT_BATCH(GEN7_3DSTATE_STENCIL_BUFFER << 16 | (5 - 2));
+ /* The stencil buffer has quirky pitch requirements. From the Graphics
+ * BSpec: vol2a.11 3D Pipeline Windower > Early Depth/Stencil Processing
+ * > Depth/Stencil Buffer State > 3DSTATE_STENCIL_BUFFER [DevIVB+],
+ * field "Surface Pitch":
+ *
+ * The pitch must be set to 2x the value computed based on width, as
+ * the stencil buffer is stored with two rows interleaved.
+ *
+ * (Note that it is not 100% clear whether this intended to apply to
+ * Gen7; the BSpec flags this comment as "DevILK,DevSNB" (which would
+ * imply that it doesn't), however the comment appears on a "DevIVB+"
+ * page (which would imply that it does). Experiments with the hardware
+ * indicate that it does.
+ */
+ OUT_BATCH(HSW_STENCIL_ENABLED | mocs_wb << 22 |
+ (2 * stencil_mt->pitch - 1));
+ OUT_RELOC64(stencil_mt->bo,
+ I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER, 0);
+ OUT_BATCH(stencil_mt ? stencil_mt->qpitch >> 2 : 0);
+ ADVANCE_BATCH();
+ }
+
+ BEGIN_BATCH(3);
+ OUT_BATCH(GEN7_3DSTATE_CLEAR_PARAMS << 16 | (3 - 2));
+ OUT_BATCH(depth_mt ? depth_mt->depth_clear_value : 0);
+ OUT_BATCH(1);
+ ADVANCE_BATCH();
+
+ brw->no_depth_or_stencil = !depth_mt && !stencil_mt;
+}
+
+/* Awful vtable-compatible function; should be cleaned up in the future. */
void
gen8_emit_depth_stencil_hiz(struct brw_context *brw,
struct intel_mipmap_tree *depth_mt,
const struct intel_renderbuffer *irb = NULL;
const struct gl_renderbuffer *rb = NULL;
- intel_emit_depth_stall_flushes(brw);
-
irb = intel_get_renderbuffer(fb, BUFFER_DEPTH);
if (!irb)
irb = intel_get_renderbuffer(fb, BUFFER_STENCIL);
rb = (struct gl_renderbuffer *) irb;
if (rb) {
- depth = MAX2(rb->Depth, 1);
+ depth = MAX2(irb->layer_count, 1);
if (rb->TexImage)
gl_target = rb->TexImage->TexObject->Target;
}
surftype = BRW_SURFACE_2D;
depth *= 6;
break;
+ case GL_TEXTURE_3D:
+ assert(mt);
+ depth = MAX2(mt->logical_depth0, 1);
+ surftype = translate_tex_target(gl_target);
+ break;
+ case GL_TEXTURE_1D_ARRAY:
+ case GL_TEXTURE_1D:
+ if (brw->gen >= 9) {
+ /* WaDisable1DDepthStencil. Skylake+ doesn't support 1D depth
+ * textures but it does allow pretending it's a 2D texture
+ * instead.
+ */
+ surftype = BRW_SURFACE_2D;
+ break;
+ }
+ /* fallthrough */
default:
surftype = translate_tex_target(gl_target);
break;
}
- if (fb->MaxNumLayers > 0 || !irb) {
- min_array_element = 0;
- } else if (irb->mt->num_samples > 1) {
- /* Convert physical to logical layer. */
- min_array_element = irb->mt_layer / irb->mt->num_samples;
- } else {
- min_array_element = irb->mt_layer;
- }
+ min_array_element = irb ? irb->mt_layer : 0;
lod = irb ? irb->mt_level - irb->mt->first_level : 0;
height = mt->logical_height0;
}
- /* _NEW_BUFFERS, _NEW_DEPTH, _NEW_STENCIL */
- BEGIN_BATCH(8);
- OUT_BATCH(GEN7_3DSTATE_DEPTH_BUFFER << 16 | (8 - 2));
- OUT_BATCH((surftype << 29) |
- ((ctx->Depth.Mask != 0) << 28) |
- ((stencil_mt != NULL && ctx->Stencil._WriteEnabled) << 27) |
- ((hiz ? 1 : 0) << 22) |
- (depthbuffer_format << 18) |
- (depth_mt ? depth_mt->region->pitch - 1 : 0));
- if (depth_mt) {
- OUT_RELOC64(depth_mt->region->bo,
- I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
- 0);
- } else {
- OUT_BATCH(0);
- OUT_BATCH(0);
+ emit_depth_packets(brw, depth_mt, brw_depthbuffer_format(brw), surftype,
+ ctx->Depth.Mask != 0,
+ stencil_mt, ctx->Stencil._WriteEnabled,
+ hiz, width, height, depth, lod, min_array_element);
+}
+
+/**
+ * Should we set the PMA FIX ENABLE bit?
+ *
+ * To avoid unnecessary depth related stalls, we need to set this bit.
+ * However, there is a very complicated formula which governs when it
+ * is legal to do so. This function computes that.
+ *
+ * See the documenation for the CACHE_MODE_1 register, bit 11.
+ */
+static bool
+pma_fix_enable(const struct brw_context *brw)
+{
+ const struct gl_context *ctx = &brw->ctx;
+ /* _NEW_BUFFERS */
+ struct intel_renderbuffer *depth_irb =
+ intel_get_renderbuffer(ctx->DrawBuffer, BUFFER_DEPTH);
+
+ /* 3DSTATE_WM::ForceThreadDispatch is never used. */
+ const bool wm_force_thread_dispatch = false;
+
+ /* 3DSTATE_RASTER::ForceSampleCount is never used. */
+ const bool raster_force_sample_count_nonzero = false;
+
+ /* _NEW_BUFFERS:
+ * 3DSTATE_DEPTH_BUFFER::SURFACE_TYPE != NULL &&
+ * 3DSTATE_DEPTH_BUFFER::HIZ Enable
+ */
+ const bool hiz_enabled = depth_irb && intel_renderbuffer_has_hiz(depth_irb);
+
+ /* 3DSTATE_WM::Early Depth/Stencil Control != EDSC_PREPS (2).
+ * We always leave this set to EDSC_NORMAL (0).
+ */
+ const bool edsc_not_preps = true;
+
+ /* 3DSTATE_PS_EXTRA::PixelShaderValid is always true. */
+ const bool pixel_shader_valid = true;
+
+ /* !(3DSTATE_WM_HZ_OP::DepthBufferClear ||
+ * 3DSTATE_WM_HZ_OP::DepthBufferResolve ||
+ * 3DSTATE_WM_HZ_OP::Hierarchical Depth Buffer Resolve Enable ||
+ * 3DSTATE_WM_HZ_OP::StencilBufferClear)
+ *
+ * HiZ operations are done outside of the normal state upload, so they're
+ * definitely not happening now.
+ */
+ const bool in_hiz_op = false;
+
+ /* _NEW_DEPTH:
+ * DEPTH_STENCIL_STATE::DepthTestEnable
+ */
+ const bool depth_test_enabled = depth_irb && ctx->Depth.Test;
+
+ /* _NEW_DEPTH:
+ * 3DSTATE_WM_DEPTH_STENCIL::DepthWriteEnable &&
+ * 3DSTATE_DEPTH_BUFFER::DEPTH_WRITE_ENABLE.
+ */
+ const bool depth_writes_enabled = ctx->Depth.Mask;
+
+ /* _NEW_STENCIL:
+ * !DEPTH_STENCIL_STATE::Stencil Buffer Write Enable ||
+ * !3DSTATE_DEPTH_BUFFER::Stencil Buffer Enable ||
+ * !3DSTATE_STENCIL_BUFFER::Stencil Buffer Enable
+ */
+ const bool stencil_writes_enabled = ctx->Stencil._WriteEnabled;
+
+ /* BRW_NEW_FS_PROG_DATA:
+ * 3DSTATE_PS_EXTRA::Pixel Shader Computed Depth Mode != PSCDEPTH_OFF
+ */
+ const bool ps_computes_depth =
+ brw->wm.prog_data->computed_depth_mode != BRW_PSCDEPTH_OFF;
+
+ /* BRW_NEW_FS_PROG_DATA: 3DSTATE_PS_EXTRA::PixelShaderKillsPixels
+ * BRW_NEW_FS_PROG_DATA: 3DSTATE_PS_EXTRA::oMask Present to RenderTarget
+ * _NEW_MULTISAMPLE: 3DSTATE_PS_BLEND::AlphaToCoverageEnable
+ * _NEW_COLOR: 3DSTATE_PS_BLEND::AlphaTestEnable
+ *
+ * 3DSTATE_WM_CHROMAKEY::ChromaKeyKillEnable is always false.
+ * 3DSTATE_WM::ForceKillPix != ForceOff is always true.
+ */
+ const bool kill_pixel =
+ brw->wm.prog_data->uses_kill ||
+ brw->wm.prog_data->uses_omask ||
+ (ctx->Multisample._Enabled && ctx->Multisample.SampleAlphaToCoverage) ||
+ ctx->Color.AlphaEnabled;
+
+ /* The big formula in CACHE_MODE_1::NP PMA FIX ENABLE. */
+ return !wm_force_thread_dispatch &&
+ !raster_force_sample_count_nonzero &&
+ hiz_enabled &&
+ edsc_not_preps &&
+ pixel_shader_valid &&
+ !in_hiz_op &&
+ depth_test_enabled &&
+ (ps_computes_depth ||
+ (kill_pixel && (depth_writes_enabled || stencil_writes_enabled)));
+}
+
+static void
+write_pma_stall_bits(struct brw_context *brw, uint32_t pma_stall_bits)
+{
+ struct gl_context *ctx = &brw->ctx;
+
+ /* If we haven't actually changed the value, bail now to avoid unnecessary
+ * pipeline stalls and register writes.
+ */
+ if (brw->pma_stall_bits == pma_stall_bits)
+ return;
+
+ brw->pma_stall_bits = pma_stall_bits;
+
+ /* According to the PIPE_CONTROL documentation, software should emit a
+ * PIPE_CONTROL with the CS Stall and Depth Cache Flush bits set prior
+ * to the LRI. If stencil buffer writes are enabled, then a Render Cache
+ * Flush is also necessary.
+ */
+ const uint32_t render_cache_flush =
+ ctx->Stencil._WriteEnabled ? PIPE_CONTROL_RENDER_TARGET_FLUSH : 0;
+ brw_emit_pipe_control_flush(brw,
+ PIPE_CONTROL_CS_STALL |
+ PIPE_CONTROL_DEPTH_CACHE_FLUSH |
+ render_cache_flush);
+
+ /* CACHE_MODE_1 is a non-privileged register. */
+ BEGIN_BATCH(3);
+ OUT_BATCH(MI_LOAD_REGISTER_IMM | (3 - 2));
+ OUT_BATCH(GEN7_CACHE_MODE_1);
+ OUT_BATCH(GEN8_HIZ_PMA_MASK_BITS | pma_stall_bits);
+ ADVANCE_BATCH();
+
+ /* After the LRI, a PIPE_CONTROL with both the Depth Stall and Depth Cache
+ * Flush bits is often necessary. We do it regardless because it's easier.
+ * The render cache flush is also necessary if stencil writes are enabled.
+ */
+ brw_emit_pipe_control_flush(brw,
+ PIPE_CONTROL_DEPTH_STALL |
+ PIPE_CONTROL_DEPTH_CACHE_FLUSH |
+ render_cache_flush);
+
+}
+
+static void
+gen8_emit_pma_stall_workaround(struct brw_context *brw)
+{
+ uint32_t bits = 0;
+
+ if (brw->gen >= 9)
+ return;
+
+ if (pma_fix_enable(brw))
+ bits |= GEN8_HIZ_NP_PMA_FIX_ENABLE | GEN8_HIZ_NP_EARLY_Z_FAILS_DISABLE;
+
+ write_pma_stall_bits(brw, bits);
+}
+
+const struct brw_tracked_state gen8_pma_fix = {
+ .dirty = {
+ .mesa = _NEW_BUFFERS |
+ _NEW_COLOR |
+ _NEW_DEPTH |
+ _NEW_MULTISAMPLE |
+ _NEW_STENCIL,
+ .brw = BRW_NEW_FS_PROG_DATA,
+ },
+ .emit = gen8_emit_pma_stall_workaround
+};
+
+/**
+ * Emit packets to perform a depth/HiZ resolve or fast depth/stencil clear.
+ *
+ * See the "Optimized Depth Buffer Clear and/or Stencil Buffer Clear" section
+ * of the hardware documentation for details.
+ */
+void
+gen8_hiz_exec(struct brw_context *brw, struct intel_mipmap_tree *mt,
+ unsigned int level, unsigned int layer, enum gen6_hiz_op op)
+{
+ if (op == GEN6_HIZ_OP_NONE)
+ return;
+
+ /* Disable the PMA stall fix since we're about to do a HiZ operation. */
+ if (brw->gen == 8)
+ write_pma_stall_bits(brw, 0);
+
+ assert(mt->first_level == 0);
+ assert(mt->logical_depth0 >= 1);
+
+ /* If we're operating on LOD 0, align to 8x4 to meet the alignment
+ * requirements for most HiZ operations. Otherwise, use the actual size
+ * to allow the hardware to calculate the miplevel offsets correctly.
+ */
+ uint32_t surface_width = ALIGN(mt->logical_width0, level == 0 ? 8 : 1);
+ uint32_t surface_height = ALIGN(mt->logical_height0, level == 0 ? 4 : 1);
+
+ /* From the documentation for 3DSTATE_WM_HZ_OP: "3DSTATE_MULTISAMPLE packet
+ * must be used prior to this packet to change the Number of Multisamples.
+ * This packet must not be used to change Number of Multisamples in a
+ * rendering sequence."
+ */
+ if (brw->num_samples != mt->num_samples) {
+ gen8_emit_3dstate_multisample(brw, mt->num_samples);
+ brw->NewGLState |= _NEW_MULTISAMPLE;
}
- OUT_BATCH(((width - 1) << 4) | ((height - 1) << 18) | lod);
- OUT_BATCH(((depth - 1) << 21) | (min_array_element << 10));
+
+ /* The basic algorithm is:
+ * - If needed, emit 3DSTATE_{DEPTH,HIER_DEPTH,STENCIL}_BUFFER and
+ * 3DSTATE_CLEAR_PARAMS packets to set up the relevant buffers.
+ * - If needed, emit 3DSTATE_DRAWING_RECTANGLE.
+ * - Emit 3DSTATE_WM_HZ_OP with a bit set for the particular operation.
+ * - Do a special PIPE_CONTROL to trigger an implicit rectangle primitive.
+ * - Emit 3DSTATE_WM_HZ_OP with no bits set to return to normal rendering.
+ */
+ emit_depth_packets(brw, mt,
+ brw_depth_format(brw, mt->format),
+ BRW_SURFACE_2D,
+ true, /* depth writes */
+ NULL, false, /* no stencil for now */
+ true, /* hiz */
+ surface_width,
+ surface_height,
+ mt->logical_depth0,
+ level,
+ layer); /* min_array_element */
+
+ /* Depth buffer clears and HiZ resolves must use an 8x4 aligned rectangle.
+ * Note that intel_miptree_level_enable_hiz disables HiZ for miplevels > 0
+ * which aren't 8x4 aligned, so expanding the size is safe - it'll just
+ * draw into empty padding space.
+ */
+ unsigned rect_width = ALIGN(minify(mt->logical_width0, level), 8);
+ unsigned rect_height = ALIGN(minify(mt->logical_height0, level), 4);
+
+ BEGIN_BATCH(4);
+ OUT_BATCH(_3DSTATE_DRAWING_RECTANGLE << 16 | (4 - 2));
+ OUT_BATCH(0);
+ OUT_BATCH(((rect_width - 1) & 0xffff) | ((rect_height - 1) << 16));
OUT_BATCH(0);
- OUT_BATCH(depth_mt ? depth_mt->qpitch >> 2 : 0);
ADVANCE_BATCH();
- assert(!hiz); /* TODO: Implement HiZ. */
+ /* Emit 3DSTATE_WM_HZ_OP to override pipeline state for the particular
+ * resolve or clear operation we want to perform.
+ */
+ uint32_t dw1 = 0;
+
+ switch (op) {
+ case GEN6_HIZ_OP_DEPTH_RESOLVE:
+ dw1 |= GEN8_WM_HZ_DEPTH_RESOLVE;
+ break;
+ case GEN6_HIZ_OP_HIZ_RESOLVE:
+ dw1 |= GEN8_WM_HZ_HIZ_RESOLVE;
+ break;
+ case GEN6_HIZ_OP_DEPTH_CLEAR:
+ dw1 |= GEN8_WM_HZ_DEPTH_CLEAR;
+ break;
+ case GEN6_HIZ_OP_NONE:
+ unreachable("Should not get here.");
+ }
+
+ if (mt->num_samples > 0)
+ dw1 |= SET_FIELD(ffs(mt->num_samples) - 1, GEN8_WM_HZ_NUM_SAMPLES);
+
BEGIN_BATCH(5);
- OUT_BATCH(GEN7_3DSTATE_HIER_DEPTH_BUFFER << 16 | (5 - 2));
+ OUT_BATCH(_3DSTATE_WM_HZ_OP << 16 | (5 - 2));
+ OUT_BATCH(dw1);
+ OUT_BATCH(0);
+ OUT_BATCH(SET_FIELD(rect_width, GEN8_WM_HZ_CLEAR_RECTANGLE_X_MAX) |
+ SET_FIELD(rect_height, GEN8_WM_HZ_CLEAR_RECTANGLE_Y_MAX));
+ OUT_BATCH(SET_FIELD(0xFFFF, GEN8_WM_HZ_SAMPLE_MASK));
+ ADVANCE_BATCH();
+
+ /* Emit a PIPE_CONTROL with "Post-Sync Operation" set to "Write Immediate
+ * Data", and no other bits set. This causes 3DSTATE_WM_HZ_OP's state to
+ * take effect, and spawns a rectangle primitive.
+ */
+ brw_emit_pipe_control_write(brw,
+ PIPE_CONTROL_WRITE_IMMEDIATE,
+ brw->workaround_bo, 0, 0, 0);
+
+ /* Emit 3DSTATE_WM_HZ_OP again to disable the state overrides. */
+ BEGIN_BATCH(5);
+ OUT_BATCH(_3DSTATE_WM_HZ_OP << 16 | (5 - 2));
OUT_BATCH(0);
OUT_BATCH(0);
OUT_BATCH(0);
OUT_BATCH(0);
ADVANCE_BATCH();
- if (stencil_mt == NULL) {
- BEGIN_BATCH(5);
- OUT_BATCH(GEN7_3DSTATE_STENCIL_BUFFER << 16 | (5 - 2));
- OUT_BATCH(0);
- OUT_BATCH(0);
- OUT_BATCH(0);
- OUT_BATCH(0);
- ADVANCE_BATCH();
- } else {
- BEGIN_BATCH(5);
- OUT_BATCH(GEN7_3DSTATE_STENCIL_BUFFER << 16 | (5 - 2));
- /* The stencil buffer has quirky pitch requirements. From the Graphics
- * BSpec: vol2a.11 3D Pipeline Windower > Early Depth/Stencil Processing
- * > Depth/Stencil Buffer State > 3DSTATE_STENCIL_BUFFER [DevIVB+],
- * field "Surface Pitch":
- *
- * The pitch must be set to 2x the value computed based on width, as
- * the stencil buffer is stored with two rows interleaved.
- *
- * (Note that it is not 100% clear whether this intended to apply to
- * Gen7; the BSpec flags this comment as "DevILK,DevSNB" (which would
- * imply that it doesn't), however the comment appears on a "DevIVB+"
- * page (which would imply that it does). Experiments with the hardware
- * indicate that it does.
- */
- OUT_BATCH(HSW_STENCIL_ENABLED | (2 * stencil_mt->region->pitch - 1));
- OUT_RELOC64(stencil_mt->region->bo,
- I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
- brw->depthstencil.stencil_offset);
- OUT_BATCH(stencil_mt ? stencil_mt->qpitch >> 2 : 0);
- ADVANCE_BATCH();
- }
+ /* Mark this buffer as needing a TC flush, as we've rendered to it. */
+ brw_render_cache_set_add_bo(brw, mt->bo);
- BEGIN_BATCH(3);
- OUT_BATCH(GEN7_3DSTATE_CLEAR_PARAMS << 16 | (3 - 2));
- OUT_BATCH(depth_mt ? depth_mt->depth_clear_value : 0);
- OUT_BATCH(1);
- ADVANCE_BATCH();
+ /* We've clobbered all of the depth packets, and the drawing rectangle,
+ * so we need to ensure those packets are re-emitted before the next
+ * primitive.
+ *
+ * Setting _NEW_DEPTH and _NEW_BUFFERS covers it, but is rather overkill.
+ */
+ brw->NewGLState |= _NEW_DEPTH | _NEW_BUFFERS;
}