Many watchdog driver reset the watchdog device on initialization. This
is a problem if the watchdog is activated by the bootloader and should
be active the whole time until the userspace can write to it.
This patch adds a module parameter (watchdog.activate_first) that
activates the first registered watchdog. Using this parameter it is
possible to have an active watchdog during the whole boot process.
Signed-off-by: Markus Pargmann <mpa@xxxxxxxxxxxxxx>
---
drivers/watchdog/watchdog_core.c | 4 ++++
drivers/watchdog/watchdog_core.h | 4 ++++
drivers/watchdog/watchdog_dev.c | 21 ++++++++++++++++++++-
3 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index cec9b55..6db16eb 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -43,6 +43,10 @@
static DEFINE_IDA(watchdog_ida);
static struct class *watchdog_class;
+unsigned int activate_first = 0;
+module_param(activate_first, uint, 0);
+MODULE_PARM_DESC(activate_first, "Activation timeout for first watchdog registered. 0 means no activation.");
+
static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
{
/*
diff --git a/drivers/watchdog/watchdog_core.h b/drivers/watchdog/watchdog_core.h
index 6c95141..4526170 100644
--- a/drivers/watchdog/watchdog_core.h
+++ b/drivers/watchdog/watchdog_core.h
@@ -28,6 +28,10 @@
#define MAX_DOGS 32 /* Maximum number of watchdog devices */
+/* Activate first registered watchdog and set this as the timeout value
+ * (only != 0) */
+extern unsigned int activate_first;
+
/*
* Functions/procedures to be called by the core
*/
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 6aaefba..fe60fdc 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -553,8 +553,27 @@ int watchdog_dev_register(struct watchdog_device *watchdog)
misc_deregister(&watchdog_miscdev);
old_wdd = NULL;
}
+
+ return err;
}
- return err;
+
+ if (activate_first && watchdog->id == 0) {
+ err = watchdog_set_timeout(watchdog, activate_first);
+ if (err && err != -EOPNOTSUPP) {
+ pr_err("watchdog%d failed to set timeout for first activation\n",
+ watchdog->id);
+ return err;
+ }
+
+ err = watchdog_start(watchdog);
+ if (err) {
+ pr_err("watchdog%d failed to start first watchdog\n",
+ watchdog->id);
+ return err;
+ }
+ }
+
+ return 0;
}
/*
--
1.8.5.3
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