[Mesa-dev] [PATCH] i965/icl: Disable binding table prefetching

[Anuj Phogat]

From: Topi Pohjolainen <topi.pohjolainen at intel.com>

Gen 11 workarounds table #2056 WABTPPrefetchDisable suggests to
disable prefetching of binding tables for ICLLP A0 and B0
steppings. It fixes multiple gpu hangs in
ext_framebuffer_multisample* tests on ICLLP B0 h/w.

Anuj: Add comments and commit message.
      Add gen 11 checks in the code.

Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
 src/intel/blorp/blorp_genX_exec.h             |  7 +++++++
 src/mesa/drivers/dri/i965/genX_state_upload.c | 14 +++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/intel/blorp/blorp_genX_exec.h b/src/intel/blorp/blorp_genX_exec.h
index 8bd9174b677..50341ab0ecf 100644
--- a/src/intel/blorp/blorp_genX_exec.h
+++ b/src/intel/blorp/blorp_genX_exec.h
@@ -762,6 +762,13 @@ blorp_emit_ps_config(struct blorp_batch *batch,
          ps.BindingTableEntryCount = 1;
       }
 
+     /* Gen 11 workarounds table #2056 WABTPPrefetchDisable suggests to
+      * disable prefetching of binding tables on A0 and B0 steppings.
+      * TODO: Revisit this WA on C0 stepping.
+      */
+      if (GEN_GEN == 11)
+         ps.BindingTableEntryCount = 0;
+
       if (prog_data) {
          ps._8PixelDispatchEnable = prog_data->dispatch_8;
          ps._16PixelDispatchEnable = prog_data->dispatch_16;
diff --git a/src/mesa/drivers/dri/i965/genX_state_upload.c b/src/mesa/drivers/dri/i965/genX_state_upload.c
index 9e0a17b9d93..b02acaf40e5 100644
--- a/src/mesa/drivers/dri/i965/genX_state_upload.c
+++ b/src/mesa/drivers/dri/i965/genX_state_upload.c
@@ -2165,7 +2165,13 @@ static const struct brw_tracked_state genX(wm_state) = {
    pkt.KernelStartPointer = KSP(brw, stage_state->prog_offset);           \
    pkt.SamplerCount       =                                               \
       DIV_ROUND_UP(CLAMP(stage_state->sampler_count, 0, 16), 4);          \
+   /* Gen 11 workarounds table #2056 WABTPPrefetchDisable suggests to     \
+    * disable prefetching of binding tables in A0 and B0 steppings.       \
+    * TODO: Revisit this WA on C0 stepping.                               \
+    */                                                                    \
    pkt.BindingTableEntryCount =                                           \
+      GEN_GEN == 11 ?                                                     \
+      0 :                                                                 \
       stage_prog_data->binding_table.size_bytes / 4;                      \
    pkt.FloatingPointMode  = stage_prog_data->use_alt_mode;                \
                                                                           \
@@ -3954,7 +3960,13 @@ genX(upload_ps)(struct brw_context *brw)
          DIV_ROUND_UP(CLAMP(stage_state->sampler_count, 0, 16), 4);
 
       /* BRW_NEW_FS_PROG_DATA */
-      ps.BindingTableEntryCount = prog_data->base.binding_table.size_bytes / 4;
+      /* Gen 11 workarounds table #2056 WABTPPrefetchDisable suggests to disable
+       * prefetching of binding tables in A0 and B0 steppings.
+       * TODO: Revisit this workaround on C0 stepping.
+       */
+      ps.BindingTableEntryCount = GEN_GEN == 11 ?
+                                  0 :
+                                  prog_data->base.binding_table.size_bytes / 4;
 
       if (prog_data->base.use_alt_mode)
          ps.FloatingPointMode = Alternate;
-- 
2.17.0