[PATCH v4 6/7] watchdog: alim7101: Register restart handler with restart notifier

Guenter Roeck
2014-07-13T15:31:28Z

The kernel core now provides an API to trigger a system restart.
Register with it to restart the system instead of misusing the
reboot notifier.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v4: Set restart notifier priority to 128.
v3: No change
v2: No change

drivers/watchdog/alim7101_wdt.c | 42 +++++++++++++++++++++++++++++++----------
1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/drivers/watchdog/alim7101_wdt.c b/drivers/watchdog/alim7101_wdt.c
index 996b2f7..069c2e2 100644
--- a/drivers/watchdog/alim7101_wdt.c
+++ b/drivers/watchdog/alim7101_wdt.c
@@ -301,6 +301,28 @@ static struct miscdevice wdt_miscdev = {
.fops = &wdt_fops,
};

+static int wdt_restart_notify(struct notifier_block *this, unsigned long mode,
+ void *cmd)
+{
+ /*
+ * Cobalt devices have no way of rebooting themselves other
+ * than getting the watchdog to pull reset, so we restart the
+ * watchdog on reboot with no heartbeat.
+ */
+ wdt_change(WDT_ENABLE);
+
+ /* loop until the watchdog fires */
+ while (true)
+ ;
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block wdt_restart_notifier = {
+ .notifier_call = wdt_restart_notify,
+ .priority = 128,
+};
+
/*
* Notifier for system down
*/
@@ -311,15 +333,6 @@ static int wdt_notify_sys(struct notifier_block *this,
if (code == SYS_DOWN || code == SYS_HALT)
wdt_turnoff();

- if (code == SYS_RESTART) {
- /*
- * Cobalt devices have no way of rebooting themselves other
- * than getting the watchdog to pull reset, so we restart the
- * watchdog on reboot with no heartbeat
- */
- wdt_change(WDT_ENABLE);
- pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n");
- }
return NOTIFY_DONE;
}

@@ -338,6 +351,7 @@ static void __exit alim7101_wdt_unload(void)
/* Deregister */
misc_deregister(&wdt_miscdev);
unregister_reboot_notifier(&wdt_notifier);
+ unregister_restart_notifier(&wdt_restart_notifier);
pci_dev_put(alim7101_pmu);
}

@@ -390,11 +404,17 @@ static int __init alim7101_wdt_init(void)
goto err_out;
}

+ rc = register_restart_notifier(&wdt_restart_notifier);
+ if (rc) {
+ pr_err("cannot register reboot notifier (err=%d)\n", rc);
+ goto err_out_reboot;
+ }
+
rc = misc_register(&wdt_miscdev);
if (rc) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
wdt_miscdev.minor, rc);
- goto err_out_reboot;
+ goto err_out_restart;
}

if (nowayout)
@@ -404,6 +424,8 @@ static int __init alim7101_wdt_init(void)
timeout, nowayout);
return 0;

+err_out_restart:
+ unregister_restart_notifier(&wdt_restart_notifier);
err_out_reboot:
unregister_reboot_notifier(&wdt_notifier);
err_out:
--
1.9.1