anv: add a command streamer stall on Xe2+ when switching pipelines

Xe2+ gets rid of PIPELINE_SELECT, so we need to make sure we add a stall
when switching pipelines

Signed-off-by: Rohan Garg <rohan.garg@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27823>

src/intel/vulkan/genX_cmd_buffer.c

@@ -3737,6 +3737,18 @@ genX(flush_pipeline_select)(struct anv_cmd_buffer *cmd_buffer,
       return;
 
 #if GFX_VER >= 20
+   /* While PIPELINE_SELECT is not needed on Xe2+, our current assumption
+    * is that the pipelined flushes in the 3D pipeline are not getting
+    * synchronized with the compute dispatches (and vice versa). So we need
+    * a CS_STALL prior the next set of commands to ensure the flushes have
+    * completed.
+    *
+    * The new RESOURCE_BARRIER instruction has support for synchronizing
+    * 3D/Compute and once we switch to that we should be able to get rid of
+    * this CS_STALL.
+    */
+   anv_add_pending_pipe_bits(cmd_buffer, ANV_PIPE_CS_STALL_BIT, "pipeline switch stall");
+
    /* Since we are not stalling/flushing caches explicitly while switching
     * between the pipelines, we need to apply data dependency flushes recorded
     * previously on the resource.