some fixes in perf tests

modules/core/perf/opencl/perf_channels.cpp

@@ -85,7 +85,7 @@ OCL_PERF_TEST_P(MergeFixture, Merge,
 typedef MergeParams SplitParams;
 typedef TestBaseWithParam<SplitParams> SplitFixture;
 
-OCL_PERF_TEST_P(SplitFixture, DISABLED_Split,
+OCL_PERF_TEST_P(SplitFixture, Split,
                 ::testing::Combine(OCL_TEST_SIZES, OCL_PERF_ENUM(CV_8U, CV_32F), Values(2, 3)))
 {
     const SplitParams params = GetParam();

modules/ts/src/ts_perf.cpp

@@ -876,7 +876,9 @@ void TestBase::warmup(cv::InputOutputArray a, WarmUpType wtype)
 {
     if (a.empty())
         return;
-    else if (a.isUMat() && wtype != WARMUP_READ)
+    else if (a.isUMat())
+    {
+        if (wtype == WARMUP_RNG || wtype == WARMUP_WRITE)
         {
             int depth = a.depth();
             if (depth == CV_8U)
@@ -891,7 +893,7 @@ void TestBase::warmup(cv::InputOutputArray a, WarmUpType wtype)
                 cv::randu(a, -4096, 4096);
             else
                 CV_Error(cv::Error::StsUnsupportedFormat, "Unsupported format");
-
+        }
         return;
     }
     else if (a.kind() != cv::_InputArray::STD_VECTOR_MAT && a.kind() != cv::_InputArray::STD_VECTOR_VECTOR)