Simplify warning.

Project.toml

@@ -5,7 +5,6 @@ version = "0.9.0"
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
 Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"
-CUDAdrv = "c5f51814-7f29-56b8-a69c-e4d8f6be1fde"
 CodecZlib = "944b1d66-785c-5afd-91f1-9de20f533193"
 Colors = "5ae59095-9a9b-59fe-a467-6f913c188581"
 CuArrays = "3a865a2d-5b23-5a0f-bc46-62713ec82fae"
@@ -25,7 +24,6 @@ ZipFile = "a5390f91-8eb1-5f08-bee0-b1d1ffed6cea"
 Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
 
 [compat]
-CUDAdrv = "4.0.3"
 CuArrays = "1.4.3"
 NNlib = "0.6"
 Zygote = "0.4"

src/Flux.jl

@@ -21,8 +21,7 @@ export SGD, Descent, ADAM, Momentum, Nesterov, RMSProp,
   ADAMW, RADAM, InvDecay, ExpDecay, WeightDecay
 
 
-ENV["CUDA_INIT_SILENT"] = true
-using CUDAdrv, CuArrays
+using CuArrays
 const use_cuda = Ref(false)
 
 include("utils.jl")
@@ -40,12 +39,8 @@ include("data/Data.jl")
 include("deprecations.jl")
 
 function __init__()
-  if !CUDAdrv.functional()
-    # nothing to do here, the user doesn't have CUDA
-  elseif length(devices()) == 0
-    @warn "CUDA available, but no GPU detected"
-  elseif !CuArrays.functional()
-    @warn "CUDA GPU available, but CuArrays.jl failed to load"
+  if !CuArrays.functional()
+    # nothing to do here, and either CuArrays or one of its dependencies will have warned
   else
     use_cuda[] = true
 
@@ -54,7 +49,7 @@ function __init__()
     if CuArrays.has_cudnn()
       include(joinpath(@__DIR__, "cuda/cuda.jl"))
     else
-      @warn "CUDA GPU available, but CuArrays.jl did not find libcudnn. Some functionality will not be available."
+      @warn "CuArrays.jl did not find libcudnn. Some functionality will not be available."
     end
   end
 end