Commit b5ade9bc authored Jan 27, 2015 by Doug Anderson Committed by Wim Van Sebroeck Feb 17, 2015

watchdog: dw_wdt: Try to get a 30 second watchdog by default



The dw_wdt_set_top() function takes in a value in seconds.  In
dw_wdt_open() we were calling it with a value that's supposed to
represent the maximum value programmed into the "top" register with a
comment saying that we were trying to set the watchdog to its maximum
value.  Instead we ended up setting the watchdog to ~15 seconds.

Let's fix this.  However, setting things to the "max" gives me an 86
second watchdog in the system I'm looking at.  86 seconds feels a
little too long.  We'll explicitly choose 30 seconds as a more
reasonable value.

NOTE: Ideally this driver should be transitioned to be a real watchdog
driver.  Then we could use "watchdog_init_timeout" and let the timeout
be specified in a number of ways (device tree, module parameter, etc).
This patch should be considered a bit of a stopgap solution.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

parent a0085010

drivers/watchdog/dw_wdt.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -51,6 +51,8 @@
		/* The maximum TOP (timeout period) value that can be set in the watchdog. */
		#define DW_WDT_MAX_TOP 15

		#define DW_WDT_DEFAULT_SECONDS 30

		static bool nowayout = WATCHDOG_NOWAYOUT;
		module_param(nowayout, bool, 0);
		MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
		@@ -179,9 +181,9 @@ static int dw_wdt_open(struct inode inode, struct file filp)
		if (!dw_wdt_is_enabled()) {
		/*
		* The watchdog is not currently enabled. Set the timeout to
		* the maximum and then start it.
		* something reasonable and then start it.
		*/
		dw_wdt_set_top(DW_WDT_MAX_TOP);
		dw_wdt_set_top(DW_WDT_DEFAULT_SECONDS);
		writel(WDOG_CONTROL_REG_WDT_EN_MASK,
		dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
		}