diff options
| author | Tero Kristo <t-kristo@ti.com> | 2020-07-17 15:29:56 +0200 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@linux-watchdog.org> | 2020-08-05 18:43:02 +0200 |
| commit | cef9572e9af373cefd1adc9e771e89670da5da3c (patch) | |
| tree | f80b4b40eea485aa70c4d6cf400be986dafa92af /drivers/watchdog | |
| parent | watchdog: use __watchdog_ping in startup (diff) | |
| download | linux-cef9572e9af373cefd1adc9e771e89670da5da3c.tar.xz linux-cef9572e9af373cefd1adc9e771e89670da5da3c.zip | |
watchdog: add support for adjusting last known HW keepalive time
Certain watchdogs require the watchdog only to be pinged within a
specific time window, pinging too early or too late cause the watchdog
to fire. In cases where this sort of watchdog has been started before
kernel comes up, we must adjust the watchdog keepalive window to match
the actually running timer, so add a new driver API for this purpose.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200717132958.14304-3-t-kristo@ti.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Diffstat (limited to 'drivers/watchdog')
| -rw-r--r-- | drivers/watchdog/watchdog_dev.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 0ad1c393c00e..531e74994b61 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -1139,6 +1139,36 @@ void watchdog_dev_unregister(struct watchdog_device *wdd) } /* + * watchdog_set_last_hw_keepalive: set last HW keepalive time for watchdog + * @wdd: watchdog device + * @last_ping_ms: time since last HW heartbeat + * + * Adjusts the last known HW keepalive time for a watchdog timer. + * This is needed if the watchdog is already running when the probe + * function is called, and it can't be pinged immediately. This + * function must be called immediately after watchdog registration, + * and min_hw_heartbeat_ms must be set for this to be useful. + */ +int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd, + unsigned int last_ping_ms) +{ + struct watchdog_core_data *wd_data; + ktime_t now; + + if (!wdd) + return -EINVAL; + + wd_data = wdd->wd_data; + + now = ktime_get(); + + wd_data->last_hw_keepalive = ktime_sub(now, ms_to_ktime(last_ping_ms)); + + return __watchdog_ping(wdd); +} +EXPORT_SYMBOL_GPL(watchdog_set_last_hw_keepalive); + +/* * watchdog_dev_init: init dev part of watchdog core * * Allocate a range of chardev nodes to use for watchdog devices |