Hi,

I am currently using Resnet50 and calculate the gradient w.r.t the input, which is something like:

`grad_val = pred.backward(create_graph=True)`

Then I use the grad to further calculate:

`grad_val.requires_grad_()`

`result = autograd.grad(grad_val, model.parameters())`

I find that the last item of the result is always None. Normally, it should be the same shape as bias term, right?

Thanks,