If you've got code that does this in a tight loop 1. Open watchdog 2. Send 'expect close' 3. Close watchdog ...you'll eventually trigger a watchdog reset. You can reproduce this by using daisydog (1) and running: while true; do daisydog -c > /dev/null; done The problem is that each time you write to the watchdog for 'expect close' it moves the timer .5 seconds out. The timer thus never fires and never pats the watchdog for you. 1: http://git.chromium.org/gitweb/?p=chromiumos/third_party/daisydog.git Signed-off-by: Doug Anderson <dianders@xxxxxxxxxxxx> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> Tested-by: Jisheng Zhang <jszhang@xxxxxxxxxxx> --- Changes in v2: None drivers/watchdog/dw_wdt.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index a284abd..6ea0634 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -215,6 +215,7 @@ static ssize_t dw_wdt_write(struct file *filp, const char __user *buf, } dw_wdt_set_next_heartbeat(); + dw_wdt_keepalive(); mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT); return len; -- 2.2.0.rc0.207.ga3a616c -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
