Using LSTM network on tensorflow with nnapi fails

I followed Building Machine Learning Software with Reference Images for Yocto Project | Toradex Developer Center and that seems to work just fine.

However, when running my custom network (which contains an LSTM layer) it fails with the following message when I run the tensorflow lite benchmark with --use_nnapi=true:

E [vsi_nn_kernel_create_node:656]Load client node from kernel com.vivantecorp.extension.cl.lstmunit_activation_S_F32toF32_F32_SIGMOID fail with -7.

E [vsi_nn_kernel_create_node:656]Load client node from kernel com.vivantecorp.extension.cpu.lstmunit_activation fail with -7.
W [vsi_nn_kernel_selector:977]No valid kernel for lstmunit_activation
E [vsi_nn_internal_compute_node:615]op_compute fail 79
E [vsi_nn_internal_compute_node:615]op_compute fail 80
E [compute_node:354]Create node[1] LSTM_OVXLIB fail

This is unexpected as the LSTM operation is supposed to be supported.
Anyone knows what is going on here?

Hi @sannenj

Thanks for writing to the Toradex Community!

Could you provide the version of the hardware and software of your module?

I think in your case, you are using a custom image. Could you let us know how you created the custom image?
Please share also information about how we can reproduce the issue?

Thanks and best regards,
Jaski

Yes I have created a custom image. I have created it using the steps as described in the linked article.
I have an Ixora 1.1A and an Apalis 1.2B imx8qm.

For reproducing the issue you need to run the tensorflow benchmark application with a model that has an lstm unit. Unfortunately I am not allowed to share the model I am using. I will try to reproduce first with a publicly available network and then let you know.

Hi,
Thanks for the information. We will wait for your example where we can reproduce this issue.

Thanks and best regards,
Jaski

Hi @sannenj

Were you able to create an example with a public network.

Best regards,
Jaski

Unfortunately not. I could not spend much time on it and was not able to find such a model yet. I did find some but they were not in tflite format. It will probably take a while as this now has very low priority within my company. :frowning:

Hi @sannenj

Thanks for your feedback. Feel free to write us once you found such a model.
Best regards,
Jaski