According to the SBSA specification the Watchdog Compare Register is split into two separate 32bit registers. EDK2 code uses a single 64bit transaction to update them, which can be problematic, depending on the SoC implementation and could result in an unpredicted behavior.
Fix this by modifying WatchdogWriteCompareRegister routine to use two consecutive 32bit writes to the Watchdog Compare Register Low and High, using new dedicated macros. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Marcin Wojtas <[email protected]> Reviewed-by: Leif Lindholm <[email protected]> --- Changelog v1 -> v2: - use separate macros for WCV register low and high - improve commit message - add Leif's RB ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h | 3 ++- ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h index 9e2aebc..4f42c56 100644 --- a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h +++ b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h @@ -20,7 +20,8 @@ // Control Frame: #define GENERIC_WDOG_CONTROL_STATUS_REG ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x000) #define GENERIC_WDOG_OFFSET_REG ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x008) -#define GENERIC_WDOG_COMPARE_VALUE_REG ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x010) +#define GENERIC_WDOG_COMPARE_VALUE_REG_LOW ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x010) +#define GENERIC_WDOG_COMPARE_VALUE_REG_HIGH ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x014) // Values of bit 0 of the Control/Status Register #define GENERIC_WDOG_ENABLED 1 diff --git a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c index 3180f01..8ccf153 100644 --- a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c +++ b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c @@ -56,7 +56,8 @@ WatchdogWriteCompareRegister ( UINT64 Value ) { - MmioWrite64 (GENERIC_WDOG_COMPARE_VALUE_REG, Value); + MmioWrite32 (GENERIC_WDOG_COMPARE_VALUE_REG_LOW, Value & MAX_UINT32); + MmioWrite32 (GENERIC_WDOG_COMPARE_VALUE_REG_HIGH, (Value >> 32) & MAX_UINT32); } VOID -- 2.7.4 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
