MLBEDSW-6060: Revert patch for MLBEDSW-5582

- Issue was due to a previous patch to fix MLBEDSW-5582
- Revert fix for MLBEDSW-5582
  commit 849ff81f82c10a68898e5101930b92372bec5565,
- Made new fix for MLBEDSW-5582 that enforce
  output tensor from NPU graphs to be in NHWC format.
  This information is otherwise lost in the case when
  parts of a concatenation are placed in different custom operators
  resulting in mismatch bewteen NHWC and NHCWB16.

Signed-off-by: Johan Alfven <johan.alfven@arm.com>
Change-Id: Iab3ba29d348353c854f357836e6aa7c338ae1572

2 files changed, 9 insertions, 11 deletions

diff --git a/ethosu/vela/extract_npu_subgraphs.py b/ethosu/vela/extract_npu_subgraphs.py
index d802b51..f46f031 100644
--- a/ethosu/vela/extract_npu_subgraphs.py
+++ b/ethosu/vela/extract_npu_subgraphs.py
@@ -98,6 +98,9 @@ def rewrite_tensor_cpu_producer_npu_consumers(
 
     # Deal with output tensors for the NPU graph. These are special.
     npu_subgraph.output_tensors = [new_tens if tens == orig_tens else tens for tens in npu_subgraph.output_tensors]
+    for tens in npu_subgraph.output_tensors:
+        # Enforce output tensor from NPU graph to use normal NHWC output
+        tens.needs_linear_format = True
 
 
 def rewrite_tensor_npu_producer_cpu_consumers(
diff --git a/ethosu/vela/pass_packing.py b/ethosu/vela/pass_packing.py
index b84e455..1fefdf4 100644
--- a/ethosu/vela/pass_packing.py
+++ b/ethosu/vela/pass_packing.py
@@ -179,7 +179,7 @@ for (operation_set, incompatible_pack_flags, flags_to_set, flags_to_clear) in te
 
 
 def pack_into_passes(nng, arch, verbose_packing=False):
-    def visit_op(op, multiple_ops=None):
+    def visit_op(op, ignored):
         visit_op_refcount[op] += 1
 
         if visit_op_refcount[op] == 1:  # First-time visit, go and fix up unused output tensors
@@ -187,6 +187,7 @@ def pack_into_passes(nng, arch, verbose_packing=False):
                 if len(tens.consumers()) == 0:
                     visit_op_refcount[op] += 1
 
+        assert visit_op_refcount[op] <= len(op.outputs)
         if visit_op_refcount[op] == len(op.outputs):
 
             if op.type in startup_init_ops:
@@ -197,9 +198,9 @@ def pack_into_passes(nng, arch, verbose_packing=False):
                     ofm_tensor = op.outputs[0]
                 ofm_shape = op.ofm_shapes[0] if op.run_on_npu else None
 
-                build_pass((op,), ofm_tensor, ofm_shape, multiple_ops)
+                build_pass((op,), ofm_tensor, ofm_shape)
 
-    def build_pass(start_ops_to_process, ofm_tensor=None, ofm_shape=None, multiple_ops=None):
+    def build_pass(start_ops_to_process, ofm_tensor=None, ofm_shape=None):
         reverse_ops_list = []
         curr_flags = PassFlags.Empty
         npu_block_type = NpuBlockType.Default
@@ -372,10 +373,6 @@ def pack_into_passes(nng, arch, verbose_packing=False):
 
         reverse_pass_list.append(ps)
 
-        if multiple_ops:
-            multiple_op_next = multiple_ops.pop(0)
-            visit_op(multiple_op_next, multiple_ops)
-
         for inp, refcount in input_refcounts.items():
             for _ in range(refcount):
                 visit_tensor(inp)
@@ -386,10 +383,8 @@ def pack_into_passes(nng, arch, verbose_packing=False):
         visit_tensor_refcount[tens] += 1
         assert visit_tensor_refcount[tens] <= len(tens.consumers())
         if visit_tensor_refcount[tens] == len(tens.consumers()):
-            if tens.ops:
-                op = tens.ops[0]
-                multiple_ops = [o for o in tens.ops if o != op]
-                visit_op(op, multiple_ops)
+            for op in reversed(tens.ops):
+                visit_op(op, tens)
 
     def create_primary_op(op_list):
         if any(op.type in (npu_post_ops | npu_post_fuse_limited_ops) and op.run_on_npu for op in op_list):