When using CONFIG_(SPL_)WDT, the watchdog_reset function is a lot more complicated than just poking a few SOC-specific registers - it involves accessing all kinds of global data, and if the interrupt happens at the wrong time (say, in the middle of an WATCHDOG_RESET() call from ordinary code), that can end up corrupting said global data.
Also, having WATCHDOG_RESET() called automatically from the timer interrupt runs counter to the idea of a watchdog device - if the board runs into an infinite loops with interrupts still enabled, the watchdog will never fire.
Allow the board to opt out of this behaviour by setting CONFIG_SYS_WATCHDOG_FREQ to 0 - as that setting is currently nonsensical, it cannot affect any existing boards.
Signed-off-by: Rasmus Villemoes rasmus.villemoes@prevas.dk --- v2: add comment explaining the semantics of setting CONFIG_SYS_WATCHDOG_FREQ to 0.
arch/powerpc/lib/interrupts.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/lib/interrupts.c b/arch/powerpc/lib/interrupts.c index 64ee0cc210..b213e40578 100644 --- a/arch/powerpc/lib/interrupts.c +++ b/arch/powerpc/lib/interrupts.c @@ -79,7 +79,12 @@ void timer_interrupt(struct pt_regs *regs) timestamp++;
#if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG) - if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) + /* + * Setting CONFIG_SYS_WATCHDOG_FREQ to 0 can be used to + * disable calling WATCHDOG_RESET() from the timer interrupt + * function. + */ + if (CONFIG_SYS_WATCHDOG_FREQ && (timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) WATCHDOG_RESET (); #endif /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */