[Mesa-dev] [PATCH v2 4/4] i965/gen10: Implement Wa3DStateMode

[Anuj Phogat]

V2: Remove the bits enabling Float blend optimization. It is
    enabled through CACHE_MODE_SS register.
    Update the comment.

This workaround doesn't fix any of the piglit hangs we've seen
on CNL.

Cc: Nanley Chery <nanley.g.chery at intel.com>
Cc: Jason Ekstrand <jason at jlekstrand.net>
Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
Reviewed-by: Rafael Antognolli <rafael.antognolli at intel.com>
---
 src/mesa/drivers/dri/i965/brw_defines.h      |  2 ++
 src/mesa/drivers/dri/i965/brw_state_upload.c | 12 ++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index 3008a1b8a7..1c2f06546e 100644
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -1333,6 +1333,8 @@ enum brw_pixel_shader_coverage_mask_mode {
 /* DW2: start address */
 /* DW3: end address. */
 
+#define _3DSTATE_3D_MODE                     0x791e
+
 #define CMD_MI_FLUSH                  0x0200
 
 # define BLT_X_SHIFT					0
diff --git a/src/mesa/drivers/dri/i965/brw_state_upload.c b/src/mesa/drivers/dri/i965/brw_state_upload.c
index 7df06a6e4d..76c137c90e 100644
--- a/src/mesa/drivers/dri/i965/brw_state_upload.c
+++ b/src/mesa/drivers/dri/i965/brw_state_upload.c
@@ -89,6 +89,18 @@ brw_upload_initial_gpu_state(struct brw_context *brw)
       brw_load_register_imm32(brw, GEN10_CACHE_MODE_SS,
                               REG_MASK(GEN10_FLOAT_BLEND_OPTIMIZATION_ENABLE) |
                               GEN10_FLOAT_BLEND_OPTIMIZATION_ENABLE);
+
+      /* From gen10 workaround table in h/w specs:
+       * "On 3DSTATE_3D_MODE, driver must always program bits 31:16 of DW1
+       *  a value of 0xFFFF"
+       *  This means that we end up setting the entire 3D_MODE state. Bits
+       *  in this register control things such as slice hashing and we want
+       *  the default values of zero at the moment.
+       */
+      BEGIN_BATCH(2);
+      OUT_BATCH(_3DSTATE_3D_MODE  << 16 | (2 - 2));
+      OUT_BATCH(0xFFFF << 16);
+      ADVANCE_BATCH();
    }
 
    if (devinfo->gen >= 8) {
-- 
2.13.5