diff options
| -rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 9 | ||||
| -rw-r--r-- | drivers/watchdog/watchdog_dev.c | 79 | ||||
| -rw-r--r-- | include/linux/watchdog.h | 1 |
3 files changed, 80 insertions, 9 deletions
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index abbcf2ce8f62..429f81bf0cf7 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -56,8 +56,9 @@ It contains following fields: This data should only be accessed via the watchdog_set_drvadata and watchdog_get_drvdata routines. * status: this field contains a number of status bits that give extra - information about the status of the device (Like: is the device opened via - the /dev/watchdog interface or not, ...). + information about the status of the device (Like: is the watchdog timer + running/active, is the device opened via the /dev/watchdog interface or not, + ...). The list of watchdog operations is defined as: @@ -109,6 +110,10 @@ they are supported. These optional routines/operations are: The status bits should (preferably) be set with the set_bit and clear_bit alike bit-operations. The status bits that are defined are: +* WDOG_ACTIVE: this status bit indicates whether or not a watchdog timer device + is active or not. When the watchdog is active after booting, then you should + set this status bit (Note: when you register the watchdog timer device with + this bit set, then opening /dev/watchdog will skip the start operation) * WDOG_DEV_OPEN: this status bit shows whether or not the watchdog device was opened via /dev/watchdog. (This bit should only be used by the WatchDog Timer Driver Core). diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 2fb4cecd50d8..9f5550e16ab5 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -54,14 +54,64 @@ static struct watchdog_device *wdd; * If the watchdog has no own ping operation then it needs to be * restarted via the start operation. This wrapper function does * exactly that. + * We only ping when the watchdog device is running. */ static int watchdog_ping(struct watchdog_device *wddev) { - if (wddev->ops->ping) - return wddev->ops->ping(wddev); /* ping the watchdog */ - else - return wddev->ops->start(wddev); /* restart the watchdog */ + if (test_bit(WDOG_ACTIVE, &wdd->status)) { + if (wddev->ops->ping) + return wddev->ops->ping(wddev); /* ping the watchdog */ + else + return wddev->ops->start(wddev); /* restart watchdog */ + } + return 0; +} + +/* + * watchdog_start: wrapper to start the watchdog. + * @wddev: the watchdog device to start + * + * Start the watchdog if it is not active and mark it active. + * This function returns zero on success or a negative errno code for + * failure. + */ + +static int watchdog_start(struct watchdog_device *wddev) +{ + int err; + + if (!test_bit(WDOG_ACTIVE, &wdd->status)) { + err = wddev->ops->start(wddev); + if (err < 0) + return err; + + set_bit(WDOG_ACTIVE, &wdd->status); + } + return 0; +} + +/* + * watchdog_stop: wrapper to stop the watchdog. + * @wddev: the watchdog device to stop + * + * Stop the watchdog if it is still active and unmark it active. + * This function returns zero on success or a negative errno code for + * failure. + */ + +static int watchdog_stop(struct watchdog_device *wddev) +{ + int err; + + if (test_bit(WDOG_ACTIVE, &wdd->status)) { + err = wddev->ops->stop(wddev); + if (err < 0) + return err; + + clear_bit(WDOG_ACTIVE, &wdd->status); + } + return 0; } /* @@ -110,6 +160,7 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, void __user *argp = (void __user *)arg; int __user *p = argp; unsigned int val; + int err; switch (cmd) { case WDIOC_GETSUPPORT: @@ -120,6 +171,20 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, return put_user(val, p); case WDIOC_GETBOOTSTATUS: return put_user(wdd->bootstatus, p); + case WDIOC_SETOPTIONS: + if (get_user(val, p)) + return -EFAULT; + if (val & WDIOS_DISABLECARD) { + err = watchdog_stop(wdd); + if (err < 0) + return err; + } + if (val & WDIOS_ENABLECARD) { + err = watchdog_start(wdd); + if (err < 0) + return err; + } + return 0; case WDIOC_KEEPALIVE: if (!(wdd->info->options & WDIOF_KEEPALIVEPING)) return -EOPNOTSUPP; @@ -155,7 +220,7 @@ static int watchdog_open(struct inode *inode, struct file *file) if (!try_module_get(wdd->ops->owner)) goto out; - err = wdd->ops->start(wdd); + err = watchdog_start(wdd); if (err < 0) goto out_mod; @@ -181,8 +246,8 @@ static int watchdog_release(struct inode *inode, struct file *file) { int err; - err = wdd->ops->stop(wdd); - if (err != 0) { + err = watchdog_stop(wdd); + if (err < 0) { pr_crit("%s: watchdog did not stop!\n", wdd->info->identity); watchdog_ping(wdd); } diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h index 29ff80807dd4..db46fe89563e 100644 --- a/include/linux/watchdog.h +++ b/include/linux/watchdog.h @@ -106,6 +106,7 @@ struct watchdog_device { void *driver_data; unsigned long status; /* Bit numbers for status flags */ +#define WDOG_ACTIVE 0 /* Is the watchdog running/active */ #define WDOG_DEV_OPEN 1 /* Opened via /dev/watchdog ? */ }; |