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 <dianders@chromium.org>
Tested-by: Jisheng Zhang <jszhang@marvell.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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 @@
}
dw_wdt_set_next_heartbeat();
+ dw_wdt_keepalive();
mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
return len;