From 17bd5cce7e25499bda4ad7862b2335098c4c5a54 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Wed, 14 Apr 2021 09:18:22 +0200 Subject: allow opting out of WATCHDOG_RESET() from timer interrupt 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. 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. Allow the board to opt out of calling WATCHDOG_RESET() from the timer interrupt handler by setting CONFIG_SYS_WATCHDOG_FREQ to 0 - as that setting is currently nonsensical (it would be compile-time divide-by-zero), it cannot affect any existing boards. Add documentation for both the existing and extended meaning of CONFIG_SYS_WATCHDOG_FREQ. Signed-off-by: Rasmus Villemoes --- drivers/timer/mpc83xx_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/timer/mpc83xx_timer.c') diff --git a/drivers/timer/mpc83xx_timer.c b/drivers/timer/mpc83xx_timer.c index 9adb4b4cabd..952293195f8 100644 --- a/drivers/timer/mpc83xx_timer.c +++ b/drivers/timer/mpc83xx_timer.c @@ -175,7 +175,7 @@ void timer_interrupt(struct pt_regs *regs) priv->timestamp++; #if defined(CONFIG_WATCHDOG) || defined(CONFIG_HW_WATCHDOG) - if ((priv->timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) + if (CONFIG_SYS_WATCHDOG_FREQ && (priv->timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) WATCHDOG_RESET(); #endif /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */ -- cgit v1.2.3