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Subject[PATCH v2 2/2] watchdog: dw_wdt: Try to get a 30 second watchdog by default
Date
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>
---
Changes in v2: None

drivers/watchdog/dw_wdt.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 2c24882..3a5155d 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -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 "
@@ -174,9 +176,9 @@ 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);
}
--
2.2.0.rc0.207.ga3a616c


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