[roc-config] Reset the GBT FIFO on config end

Author: kostorr

src/Cru/CruBar.cxx

@@ -629,6 +629,7 @@ void CruBar::configure(bool force)
       gbt.calibrateGbt(mLinkMap);
       Cru::fpllref(mLinkMap, mPdaBar, 2);
       Cru::fpllcal(mLinkMap, mPdaBar);
+      gbt.resetFifo();
     }
   }
 

src/Cru/Gbt.cxx

@@ -287,5 +287,11 @@ uint32_t Gbt::getTxClockFrequency(Link link) //In Hz
   return mPdaBar->readRegister(address / 4);
 }
 
+void Gbt::resetFifo()
+{
+  mPdaBar->writeRegister(Cru::Registers::BSP_USER_CONTROL.index, 0x80);
+  mPdaBar->writeRegister(Cru::Registers::BSP_USER_CONTROL.index, 0x0);
+}
+
 } // namespace roc
 } // namespace AliceO2

src/Cru/Gbt.h

@@ -47,6 +47,7 @@ class Gbt
   LinkStatus getStickyBit(Link link);
   uint32_t getRxClockFrequency(Link link);
   uint32_t getTxClockFrequency(Link link);
+  void resetFifo();
 
  private:
   uint32_t getSourceSelectAddress(Link link);