From 1afdfc3e6e022a4e5e9701b365c4f92554be999a Mon Sep 17 00:00:00 2001
From: Jason Ekstrand <jason.ekstrand@intel.com>
Date: Sat, 5 Mar 2016 09:19:01 -0800
Subject: [PATCH] anv/pipeline: Implement the depth compare EQUAL workaround on
 gen8+

---
 src/intel/vulkan/gen8_pipeline.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/intel/vulkan/gen8_pipeline.c b/src/intel/vulkan/gen8_pipeline.c
index e8a067851cc..4a5e8674189 100644
--- a/src/intel/vulkan/gen8_pipeline.c
+++ b/src/intel/vulkan/gen8_pipeline.c
@@ -238,6 +238,14 @@ emit_ds_state(struct anv_pipeline *pipeline,
       .BackfaceStencilTestFunction = vk_to_gen_compare_op[info->back.compareOp],
    };
 
+   /* From the Broadwell PRM:
+    *
+    *    "If Depth_Test_Enable = 1 AND Depth_Test_func = EQUAL, the
+    *    Depth_Write_Enable must be set to 0."
+    */
+   if (info->depthTestEnable && info->depthCompareOp == VK_COMPARE_OP_EQUAL)
+      wm_depth_stencil.DepthBufferWriteEnable = false;
+
    GENX(3DSTATE_WM_DEPTH_STENCIL_pack)(NULL, dw, &wm_depth_stencil);
 }
 
-- 
2.30.2