Fix for double buffered USB and other cummulative fixes

Src/main.c

@@ -135,6 +135,7 @@ void SystemClock_Config(void)
   RCC_ClkInitTypeDef RCC_ClkInitStruct;
   RCC_PeriphCLKInitTypeDef PeriphClkInit;
 
+#if 0
     /**Initializes the CPU, AHB and APB busses clocks 
     */
   RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48|RCC_OSCILLATORTYPE_HSE;
@@ -148,6 +149,32 @@ void SystemClock_Config(void)
   {
     _Error_Handler(__FILE__, __LINE__);
   }
+#else
+  /* Set FLASH latency */
+  LL_FLASH_SetLatency(LL_FLASH_LATENCY_1);
+
+  LL_RCC_HSE_EnableBypass();
+  LL_RCC_HSE_Enable();
+  while(LL_RCC_HSE_IsReady() != 1) {}
+
+  /* Main PLL configuration and activation */
+  LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSE, LL_RCC_PLL_MUL_6, LL_RCC_PREDIV_DIV_1);
+
+  LL_RCC_PLL_Enable();
+  while(LL_RCC_PLL_IsReady() != 1) {}
+
+  /* Sysclk activation on the main PLL */
+  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
+  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
+  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL) {}
+
+  /* Set APB1 prescaler */
+  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_1);
+
+  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
+  LL_SetSystemCoreClock(48000000);
+#endif
+
 
     /**Initializes the CPU, AHB and APB busses clocks 
     */