MdeModulePkg: TerminalDxe: Added a PCD to set the timer interval

This change added a PCD to set the timer interval for terminal devices to periodically query the serial port.
microsoft · May 9, 2023 · f8ea858 · f8ea858
1 parent 69909c3
commit f8ea858
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Showing 3 changed files with 20 additions and 1 deletion.
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
@@ -2314,6 +2314,11 @@
   # @Prompt The shared bit mask when Intel Tdx is enabled.
   gEfiMdeModulePkgTokenSpaceGuid.PcdTdxSharedBitMask|0x0|UINT64|0x10000025
 
+  ## MU_CHANGE - Configuring timer interval in terminal DXE driver
+  ## This PCD determines the timer interval to be set when using serial console.
+  # @Prompt Sets the serial console timer interval, in the unit of 100ns.
+  gEfiMdeModulePkgTokenSpaceGuid.PcdTerminalKeyboardTimerInterval|0x00000000|UINT32|0x00030025
+
 [PcdsPatchableInModule]
   ## Specify memory size with page number for PEI code when
   #  Loading Module at Fixed Address feature is enabled.

diff --git a/MdeModulePkg/Universal/Console/TerminalDxe/Terminal.c b/MdeModulePkg/Universal/Console/TerminalDxe/Terminal.c
@@ -375,6 +375,7 @@ StartTerminalStateMachine (
   )
 {
   EFI_STATUS  Status;
+  UINT64      TimerInterval;  // MU_CHANGE: Override the timer interval if the PCD is set
 
   Status = gBS->CreateEvent (
                   EVT_TIMER | EVT_NOTIFY_SIGNAL,
@@ -385,10 +386,21 @@ StartTerminalStateMachine (
                   );
   ASSERT_EFI_ERROR (Status);
 
+  // MU_CHANGE Starts: Override the timer interval if the PCD is set
+  if (PcdGet32 (PcdTerminalKeyboardTimerInterval) != 0) {
+    TimerInterval = PcdGet32 (PcdTerminalKeyboardTimerInterval);
+  } else if (TerminalDevice->SerialInTimeOut == 0) {
+    TimerInterval = KEYBOARD_TIMER_INTERVAL;
+  } else {
+    // We should check back when filled in half of the FIFO, the number is the unit of 100ns.
+    TimerInterval = TerminalDevice->SerialInTimeOut * FIFO_MAX_NUMBER / 2 * 10;
+  }
+
+  // MU_CHANGE Ends
   Status = gBS->SetTimer (
                   TerminalDevice->TimerEvent,
                   TimerPeriodic,
-                  KEYBOARD_TIMER_INTERVAL
+                  TimerInterval // MU_CHANGE
                   );
   ASSERT_EFI_ERROR (Status);
 

diff --git a/MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf b/MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf
@@ -90,6 +90,8 @@
   gEfiMdePkgTokenSpaceGuid.PcdDefaultTerminalType           ## SOMETIMES_CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdErrorCodeSetVariable    ## CONSUMES
 
+  gEfiMdeModulePkgTokenSpaceGuid.PcdTerminalKeyboardTimerInterval ## CONSUMES MU_CHANGE
+
 # [Event]
 # # Relative timer event set by UnicodeToEfiKey(), used to be one 2 seconds input timeout.
 # EVENT_TYPE_RELATIVE_TIMER                   ## CONSUMES