[edk2-devel] [PATCH v5 3/3] ArmPkg: Disable watchdog interaction after exiting boot services

["Rebecca Cran via groups.io" <rebecca=os.amperecomputing.com@groups.io>]

Update GenericWatchdogDxe to disable watchdog interaction after exiting
boot services. Also, move the mEfiExitBootServicesEvent event to the top
of the file with the other static variables.

Signed-off-by: Rebecca Cran <rebecca@os.amperecomputing.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
---
 ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
index d4f9fe6f4ece..51ff9bdf8cd3 100644
--- a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
+++ b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
@@ -40,6 +40,7 @@ STATIC BOOLEAN  mExitedBootServices = FALSE;
 
 STATIC EFI_HARDWARE_INTERRUPT2_PROTOCOL  *mInterruptProtocol;
 STATIC EFI_WATCHDOG_TIMER_NOTIFY         mWatchdogNotify;
+STATIC EFI_EVENT                         mEfiExitBootServicesEvent;
 
 /**
   This function returns the maximum watchdog offset register value.
@@ -122,7 +123,8 @@ WatchdogExitBootServicesEvent (
   )
 {
   WatchdogDisable ();
-  mTimerPeriod = 0;
+  mTimerPeriod        = 0;
+  mExitedBootServices = TRUE;
 }
 
 /* This function is called when the watchdog's first signal (WS0) goes high.
@@ -219,6 +221,8 @@ WatchdogRegisterHandler (
 
   @retval EFI_SUCCESS           The watchdog timer has been programmed to fire
                                 in TimerPeriod 100ns units.
+  @retval EFI_DEVICE_ERROR      Boot Services has been exited but TimerPeriod
+                                is not zero.
 
 **/
 STATIC
@@ -233,7 +237,15 @@ WatchdogSetTimerPeriod (
   UINT64  TimerFrequencyHz;
   UINT64  NumTimerTicks;
 
-  // if TimerPeriod is 0, this is a request to stop the watchdog.
+  // If we've exited Boot Services but TimerPeriod isn't zero, this
+  // indicates that the caller is doing something wrong.
+  if (mExitedBootServices && (TimerPeriod != 0)) {
+    mTimerPeriod = 0;
+    WatchdogDisable ();
+    return EFI_DEVICE_ERROR;
+  }
+
+  // If TimerPeriod is 0 this is a request to stop the watchdog.
   if (TimerPeriod == 0) {
     mTimerPeriod = 0;
     WatchdogDisable ();
@@ -337,8 +349,6 @@ STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  mWatchdogTimer = {
   WatchdogGetTimerPeriod
 };
 
-STATIC EFI_EVENT  mEfiExitBootServicesEvent;
-
 EFI_STATUS
 EFIAPI
 GenericWatchdogEntry (
-- 
2.34.1



-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#114727): https://edk2.groups.io/g/devel/message/114727
Mute This Topic: https://groups.io/mt/104037317/7686176
Group Owner: devel+owner@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io]
-=-=-=-=-=-=-=-=-=-=-=-