diff options
| -rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 20 | ||||
| -rw-r--r-- | drivers/watchdog/watchdog_core.c | 2 | ||||
| -rw-r--r-- | drivers/watchdog/watchdog_dev.c | 6 |
3 files changed, 18 insertions, 10 deletions
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index 954134a5c4a4..9eabca1d9355 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -85,7 +85,8 @@ It contains following fields: If set, the infrastructure will send heartbeats to the watchdog driver if 'timeout' is larger than max_hw_heartbeat_ms, unless WDOG_ACTIVE is set and userspace failed to send a heartbeat for at least 'timeout' - seconds. + seconds. max_hw_heartbeat_ms must be set if a driver does not implement + the stop function. * reboot_nb: notifier block that is registered for reboot notifications, for internal use only. If the driver calls watchdog_stop_on_reboot, watchdog core will stop the watchdog on such notifications. @@ -134,17 +135,20 @@ are: device. The routine needs a pointer to the watchdog timer device structure as a parameter. It returns zero on success or a negative errno code for failure. -* stop: with this routine the watchdog timer device is being stopped. - The routine needs a pointer to the watchdog timer device structure as a - parameter. It returns zero on success or a negative errno code for failure. - Some watchdog timer hardware can only be started and not be stopped. - If a watchdog can not be stopped, the watchdog driver must set the - WDOG_HW_RUNNING flag in its stop function to inform the watchdog core that - the watchdog is still running. Not all watchdog timer hardware supports the same functionality. That's why all other routines/operations are optional. They only need to be provided if they are supported. These optional routines/operations are: +* stop: with this routine the watchdog timer device is being stopped. + The routine needs a pointer to the watchdog timer device structure as a + parameter. It returns zero on success or a negative errno code for failure. + Some watchdog timer hardware can only be started and not be stopped. A + driver supporting such hardware does not have to implement the stop routine. + If a driver has no stop function, the watchdog core will set WDOG_HW_RUNNING + and start calling the driver's keepalive pings function after the watchdog + device is closed. + If a watchdog driver does not implement the stop function, it must set + max_hw_heartbeat_ms. * ping: this is the routine that sends a keepalive ping to the watchdog timer hardware. The routine needs a pointer to the watchdog timer device structure as a diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index d9b3c9c023c4..c1658fe73d58 100644 --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -199,7 +199,7 @@ static int __watchdog_register_device(struct watchdog_device *wdd) return -EINVAL; /* Mandatory operations need to be supported */ - if (wdd->ops->start == NULL || wdd->ops->stop == NULL) + if (!wdd->ops->start || (!wdd->ops->stop && !wdd->max_hw_heartbeat_ms)) return -EINVAL; watchdog_check_min_max_timeout(wdd); diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 5d3a9fa4856e..5163c3eb3428 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -246,7 +246,11 @@ static int watchdog_stop(struct watchdog_device *wdd) return -EBUSY; } - err = wdd->ops->stop(wdd); + if (wdd->ops->stop) + err = wdd->ops->stop(wdd); + else + set_bit(WDOG_HW_RUNNING, &wdd->status); + if (err == 0) { clear_bit(WDOG_ACTIVE, &wdd->status); watchdog_update_worker(wdd); |