On 02. 09. 21, 16:05, Guenter Roeck wrote:
On 9/1/21 11:55 PM, Jiri Slaby wrote:
On 03. 02. 21, 21:11, Curtis Klein wrote:
This adds the option to use a hrtimer to generate a watchdog pretimeout
event for hardware watchdogs that do not natively support watchdog
pretimeouts.
With this enabled, all watchdogs will appear to have pretimeout support
in userspace. If no pretimeout value is set, there will be no change in
the watchdog's behavior.
Hi,
on my Dell Latitude 7280, CONFIG_WATCHDOG_HRTIMER_PRETIMEOUT=y causes
all reboot, kexec, suspend to panic. Disabling that option makes it
all work again. Provided it happens very late in the process, I don't
know how to grab some logs...
Any ideas?
AFAICS the timer does not stop on reboot. I think we'll need to augment
the code
to do that.
No, it is stopped via device unregister -> watchdog_dev_unregister ->
watchdog_cdev_unregister -> watchdog_hrtimer_pretimeout_stop.
But look:
watchdog_cdev_unregister
-> wdd->wd_data = NULL;
-> watchdog_hrtimer_pretimeout_stop
-> hrtimer_cancel(&wdd->wd_data->pretimeout_timer);
The diff below obviously fixes the issue, but I don't know what the
consequences are. The other possibility would be to pass wd_data
directly to watchdog_hrtimer_pretimeout_stop.
I don't know how this can work on some machines (I verified it does).
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -1096,6 +1096,8 @@ static void watchdog_cdev_unregister(struct
watchdog_device *wdd)
watchdog_stop(wdd);
}
+ watchdog_hrtimer_pretimeout_stop(wdd);
+
mutex_lock(&wd_data->lock);
wd_data->wdd = NULL;
wdd->wd_data = NULL;
@@ -1103,7 +1105,6 @@ static void watchdog_cdev_unregister(struct
watchdog_device *wdd)
hrtimer_cancel(&wd_data->timer);
kthread_cancel_work_sync(&wd_data->work);
- watchdog_hrtimer_pretimeout_stop(wdd);
put_device(&wd_data->dev);
}
thanks,
--
js
suse labs
