Seems like https://pytorch.org/docs/stable/quantization.html#torch.nn.quantized.functional.linear 8 is not a viable option. It requires the input tensor to be unsigned, however, the operation explicitly is between two tensors that are qint8.
>>> torch.nn.quantized.functional.linear(qA[0,], qB[0,])
RuntimeError: expected scalar type QUInt8 but found QInt8