anv: disable task redistribution

If task redistribution is enabled, then some mesh shaders read
garbage from task payload.

It may be a hardware bug, or it may be our bug. Who knows :(

This change will probably negatively affect performance of task
shader-enabled workloads on multi-slice GPUs, because mesh shaders
will be executed only on the slice where task shader was spawned.

Fixes: ef04caea9b8 ("anv: Implement Mesh Shading pipeline")

Acked-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16197>

diff --git a/src/intel/vulkan/genX_pipeline.c b/src/intel/vulkan/genX_pipeline.c
index 6cacf07..ffcf911 100644 (file)
--- a/src/intel/vulkan/genX_pipeline.c
+++ b/src/intel/vulkan/genX_pipeline.c
@@ -2216,7 +2216,12 @@ emit_task_state(struct anv_graphics_pipeline *pipeline)
       redistrib.SmallTaskThreshold = 1; /* 2^N */
       redistrib.TargetMeshBatchSize = devinfo->num_slices > 2 ? 3 : 5; /* 2^N */
       redistrib.TaskRedistributionLevel = TASKREDISTRIB_BOM;
-      redistrib.TaskRedistributionMode = TASKREDISTRIB_RR_STRICT;
+
+      /* TODO: We have an unknown issue with Task Payload when task redistribution
+       * is enabled. Disable it for now.
+       * See https://gitlab.freedesktop.org/mesa/mesa/-/issues/7141
+       */
+      redistrib.TaskRedistributionMode = TASKREDISTRIB_OFF;
    }
 }