[Fix]: fix data type in fused-bias-leakyrelu for apex fp16 training (#981)

mmcv/ops/fused_bias_leakyrelu.py

@@ -45,10 +45,9 @@ class FusedBiasLeakyReLUFunctionBackward(Function):
         # The second order deviation, in fact, contains two parts, while the
         # the first part is zero. Thus, we direct consider the second part
         # which is similar with the first order deviation in implementation.
-        gradgrad_out = ext_module.fused_bias_leakyrelu(gradgrad_input,
-                                                       gradgrad_bias, out, 3,
-                                                       1, ctx.negative_slope,
-                                                       ctx.scale)
+        gradgrad_out = ext_module.fused_bias_leakyrelu(
+            gradgrad_input, gradgrad_bias.to(out.dtype), out, 3, 1,
+            ctx.negative_slope, ctx.scale)
 
         return gradgrad_out, None, None, None
 
@@ -139,7 +138,8 @@ def fused_bias_leakyrelu(input, bias, negative_slope=0.2, scale=2**0.5):
     if not input.is_cuda:
         return bias_leakyrelu_ref(input, bias, negative_slope, scale)
 
-    return FusedBiasLeakyReLUFunction.apply(input, bias, negative_slope, scale)
+    return FusedBiasLeakyReLUFunction.apply(input, bias.to(input.dtype),
+                                            negative_slope, scale)
 
 
 def bias_leakyrelu_ref(x, bias, negative_slope=0.2, scale=2**0.5):