A watchdog device may be stopped from userspace using WDIOC_SETOPTIONS
ioctl and flag WDIOS_DISABLECARD. If the device is closed after this
operation, watchdog_release() is called and status bits checked for
stopping it. Besides, if the device has not been unregistered a critical
message "watchdog did not stop!" is printed, although the ioctl may have
successfully stopped it already.
Without the patch a user application sample code like this will successfully
stop the watchdog, but the kernel will output the message
"watchdog did not stop!":
wd_fd = open("/dev/watchdog", O_RDWR);
flags = WDIOS_DISABLECARD;
ioctl(wd_fd, WDIOC_SETOPTIONS, &flags);
close(wd_fd);
Signed-off-by: Hector Palacios <hector.palac...@digi.com>
---
drivers/watchdog/watchdog_dev.c | 38 +++++++++++++++++++++-----------------
1 file changed, 21 insertions(+), 17 deletions(-)
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index ef8edec..adadbdd 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -463,24 +463,28 @@ out:
static int watchdog_release(struct inode *inode, struct file *file)
{
struct watchdog_device *wdd = file->private_data;
- int err = -EBUSY;
- /*
- * We only stop the watchdog if we received the magic character
- * or if WDIOF_MAGICCLOSE is not set. If nowayout was set then
- * watchdog_stop will fail.
- */
- if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) ||
- !(wdd->info->options & WDIOF_MAGICCLOSE))
- err = watchdog_stop(wdd);
-
- /* If the watchdog was not stopped, send a keepalive ping */
- if (err < 0) {
- mutex_lock(&wdd->lock);
- if (!test_bit(WDOG_UNREGISTERED, &wdd->status))
- dev_crit(wdd->dev, "watchdog did not stop!\n");
- mutex_unlock(&wdd->lock);
- watchdog_ping(wdd);
+ if (test_bit(WDOG_ACTIVE, &wdd->status)) {
+ int err = -EBUSY;
+
+ /*
+ * We only stop the watchdog if we received the magic character
+ * or if WDIOF_MAGICCLOSE is not set. If nowayout was set then
+ * watchdog_stop will fail.
+ */
+ if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) ||
+ !(wdd->info->options & WDIOF_MAGICCLOSE)) {
+ err = watchdog_stop(wdd);
+ }
+
+ /* If the watchdog was not stopped, send a keepalive ping */
+ if (err < 0) {
+ mutex_lock(&wdd->lock);
+ if (!test_bit(WDOG_UNREGISTERED, &wdd->status))
+ dev_crit(wdd->dev, "watchdog did not stop!\n");
+ mutex_unlock(&wdd->lock);
+ watchdog_ping(wdd);
+ }
}
/* Allow the owner module to be unloaded again */
--
1.7.9.5
--
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