move the "cpu device checking" from supportsFeatures() to queryDeviceInfo()

modules/ocl/include/opencv2/ocl/ocl.hpp

@@ -155,7 +155,7 @@ namespace cv
             static Context* getContext();
             static void setContext(Info &oclinfo);
 
-            enum {CL_DOUBLE, CL_UNIFIED_MEM, CL_CPU};
+            enum {CL_DOUBLE, CL_UNIFIED_MEM};
             bool supportsFeature(int ftype);
             size_t computeUnits();
             void* oclContext();

modules/ocl/include/opencv2/ocl/private/util.hpp

@@ -127,8 +127,9 @@ namespace cv
         // currently only support wavefront size queries
         enum DEVICE_INFO
         {
-             WAVEFRONT_SIZE,            //in AMD speak
-             WARP_SIZE = WAVEFRONT_SIZE //in nvidia speak
+            WAVEFRONT_SIZE,             //in AMD speak
+            WARP_SIZE = WAVEFRONT_SIZE, //in nvidia speak
+            IS_CPU_DEVICE               //check if the device is CPU
         };
         //info should have been pre-allocated
         void CV_EXPORTS queryDeviceInfo(DEVICE_INFO info_type, void* info);

modules/ocl/src/initialization.cpp

@@ -397,6 +397,15 @@ namespace cv
 
                 }
                 break;
+            case IS_CPU_DEVICE:
+                {
+                    cl_device_type devicetype;
+                    openCLSafeCall(clGetDeviceInfo(impl->devices[impl->devnum], 
+                                    CL_DEVICE_TYPE, sizeof(cl_device_type), 
+                                    &devicetype, NULL));
+                    *(bool*)info = (devicetype == CVCL_DEVICE_TYPE_CPU);
+                }
+                break;
             default:
                 CV_Error(-1, "Invalid device info type");
                 break;
@@ -979,12 +988,6 @@ namespace cv
                 return impl->double_support == 1;
             case CL_UNIFIED_MEM:
                 return impl->unified_memory == 1;
-            case CL_CPU:
-                cl_device_type devicetype;
-                clGetDeviceInfo(impl->devices[impl->devnum], 
-                                CL_DEVICE_TYPE, sizeof(cl_device_type), 
-                                &devicetype, NULL);
-                return devicetype == CVCL_DEVICE_TYPE_CPU;
             default:
                 return false;
             }

modules/ocl/src/pyrlk.cpp

@@ -187,7 +187,9 @@ static void lkSparse_run(oclMat &I, oclMat &J,
     args.push_back( make_pair( sizeof(cl_int), (void *)&iters ));
     args.push_back( make_pair( sizeof(cl_char), (void *)&calcErr ));
 
-    if (clCxt->supportsFeature(Context::CL_CPU))
+    bool is_cpu;
+    queryDeviceInfo(IS_CPU_DEVICE, &is_cpu);
+    if (is_cpu)
     {
         openCLExecuteKernel(clCxt, &pyrlk, kernelName, globalThreads, localThreads, args, I.oclchannels(), I.depth(), (char*)" -D CPU");
         releaseTexture(ITex);