[SmartSwitch][gNOI] DPU File.TransferToRemote fails with Internal error "failed to send content chunk: EOF

[v-cshekar]

All SmartSwitch DPU gNOI upgrade tests in  upgrade_path/test_upgrade_smart_switch_gnoi.py  fail at the gNOI  gnoi.file.File/TransferToRemote  step when the request is routed to a DPU. The NPU gNMI server returns a server-side gRPC  Internal  error:  failed to send content chunk: EOF .

Ran it the below command:

python3 -m pytest upgrade_path/test_upgrade_smart_switch_gnoi.py \
  --inventory ../ansible/str3,../ansible/veos \
  --host-pattern str3-cisco-8102-E04-U26 \
  --testbed vms69-t1-smartswitch-8102-26 \
  --testbed_file ../ansible/testbed.yaml \
  --upgrade_type=cold \
  --base_image_list=http://10.1.3.6/.../sonic-pensando-20251110.31.bin \
  --target_image_list=http://10.1.3.6/.../sonic-pensando-20251110.32.bin \
  --target_version=SONiC-OS-20251110.32 \
  --ss_target_index=0 --ss_target_indices=0 \
  --ss_npu_target_image=http://10.1.3.6/.../sonic-cisco-8000-20251110.34.bin \
  --ss_npu_target_version=SONiC-OS-20251110.34 \
  --skip_sanity

Have attached the debug logs:

dpu_upgrade_20260702_185721.log