Fix SSD/ResNet50 winograd training/test accuracy/assertion issues.

It's mainly due to mkldnn reorder implementation, which only support nchw input
format to wino_fmt output reorder.

Original framework code path may create wino_fmt to nchw and nchw16i16o to wino_fmt
reorder primitive, but those are not supported by mkldnn and will trigger assertion.

Author: ftian1

src/caffe/layers/mkldnn_convolution_layer.cpp

@@ -495,7 +495,7 @@ void MKLDNNConvolutionLayer<Dtype>::InitConvolutionFwd(const vector<Blob<Dtype>*
     fwd_top_data->name = "fwd_top_data      @ " + this->layer_param_.name();
     fwd_top_data_memory = fwd_top_data->create_output_memory();
 
-    bool is_wino = conv_algorithm == algorithm::convolution_winograd ? true : false; 
+    bool is_wino = (prv_fwd_weights_data_memory_pd->desc().data.format == memory::format::wino_fmt); 
     if (fwd_weights_data == NULL) {
       if (this->need_quantize_){
         int count = 1; //single channel

src/caffe/mkldnn_memory.cpp

@@ -153,7 +153,13 @@ template <typename Dtype, bool is_diff>
 #ifdef DEBUG
             LOG(INFO) << "Formats of blob-prv-memory-pd and this-prv-memory-pd are not equal !";
 #endif
-            this->set_extprv_memory_pd(blob_prv_mkldnn_mem_descr->prv_memory_pd(), scale, blob_prv_mkldnn_mem_descr->get_scale(), blob_prv_mkldnn_mem_descr->get_sum());
+            if (!is_wino)
+              this->set_extprv_memory_pd(blob_prv_mkldnn_mem_descr->prv_memory_pd(), scale, blob_prv_mkldnn_mem_descr->get_scale(), blob_prv_mkldnn_mem_descr->get_sum());
+            else
+              // If the blob's prv is using wino_fmt, it is only able to accept nchw to wino reorder due to mkldnn implementation. Other input formats, such as nchw16i16o
+              // to wino reorder, are not supported by mkldnn.
+              // Therefore we have to force the blob state from prv to cpu to get nchw input format at first.
+              if (is_diff) blob->mutable_cpu_diff(); else blob->mutable_cpu_data();
         }
     }
 }