GpuRecoSts: Small fixes.

reco/detectors/sts/CbmRecoSts.cxx

@@ -33,6 +33,8 @@
 
 #include <iomanip>
 
+#include <xpu/host.h>
+
 #if __has_include(<omp.h>)
 #include <omp.h>
 #endif
@@ -334,6 +336,14 @@ InitStatus CbmRecoSts::Init()
   LOG(info) << "==========================================================";
   LOG(info) << GetName() << ": Initialising ";
 
+  // Initialize xpu.
+  // TODO: This call can be relatively expensive.
+  //       We need a way to ensure this happens only once at the beginning.
+  if (fUseGpuReco) {
+    setenv("XPU_PROFILE", "1", 1);  // Always enable profiling in xpu
+    xpu::initialize();
+  }
+
   // --- Check IO-Manager
   FairRootManager* ioman = FairRootManager::Instance();
   assert(ioman);

reco/detectors/sts/experimental/CbmGpuRecoSts.cxx

@@ -190,9 +190,6 @@ void CbmGpuRecoSts::Setup(size_t maxDigisPerModule, size_t nDigitsTotal)
 
 void CbmGpuRecoSts::RunHitFinder()
 {
-  setenv("XPU_PROFILE", "1", 1);
-  xpu::initialize();
-
   auto& hfc = fHitfinderCpu;
 
   // ROCm bug: Mi100 name is an emtpy string...
@@ -368,6 +365,10 @@ void CbmGpuRecoSts::FetchDigis(size_t& maxDigisPerModule, size_t& nDigisTotal)
   CbmDigiManager* digis = CbmDigiManager::Instance();
   auto& hfc             = fHitfinderCpu;
 
+  // Remove digis from previous timeslice
+  fDigisByModuleB.clear();
+  fDigisByModuleF.clear();
+
   // FIXME: GPU reco should use regular digi class too
   nDigis      = digis->GetNofDigis(ECbmModuleId::kSts);
   nDigisTotal = 0;