From 04b1a62e6bb9b217847be874fe37a6b85ddff67e Mon Sep 17 00:00:00 2001 From: Doug Anderson Date: Thu, 7 May 2015 21:27:45 -0700 Subject: [PATCH] watchdog: dw_wdt: keepalive the watchdog at write time 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 Tested-by: Jisheng Zhang Reviewed-by: Dmitry Torokhov Reviewed-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- 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 a284abdb4fb6..6ea0634345e9 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; -- 2.39.2