Optimizer dealing with parameters without gradients

[SnowdenLee]

Hi,
I have a question about the optimizer part. If the parameters do not require gradients, why they are still added into the params, shouldn't they be filtered?

mmcv/mmcv/runner/optimizer/default_constructor.py

Lines 182 to 183 in bfdd1f9

	if not param.requires_grad:
	params.append(param_group)