Lines Matching refs:watchdog

19 Usually a userspace daemon will notify the kernel watchdog driver via the
20 /dev/watchdog special device file that userspace is still alive, at
22 usually tell the hardware watchdog that everything is in order, and
23 that the watchdog should wait for yet another little while to reset
25 notifications cease to occur, and the hardware watchdog will reset the
28 The Linux watchdog API is a rather ad-hoc construction and different
35 All drivers support the basic mode of operation, where the watchdog
36 activates as soon as /dev/watchdog is opened and will reboot unless
37 the watchdog is pinged within a certain time, this time is called the
38 timeout or margin.  The simplest way to ping the watchdog is to write
39 some data to the device.  So a very simple watchdog daemon would look
40 like this source file:  see Documentation/watchdog/src/watchdog-simple.c
43 still responding before doing the write call to ping the watchdog.
45 When the device is closed, the watchdog is disabled, unless the "Magic
47 good idea, since if there is a bug in the watchdog daemon and it
49 drivers support the configuration option "Disable watchdog shutdown on
51 the kernel, there is no way of disabling the watchdog once it has been
52 started.  So, if the watchdog daemon crashes, the system will reboot
60 watchdog unless a specific magic character 'V' has been sent to
61 /dev/watchdog just before closing the file.  If the userspace daemon
64 stop pinging the watchdog without disabling it first.  This will then
65 cause a reboot if the watchdog is not re-opened in sufficient time.
71 Pinging the watchdog using an ioctl:
75 watchdog device, so the main loop in the above program could be
87 For some drivers it is possible to modify the watchdog timeout on the
109 Some watchdog timers can be set to have a trigger go off before the
129 Not all watchdog drivers will support a pretimeout.
133 Some watchdog drivers have the ability to report the remaining time
142 All watchdog drivers are required return more information about the system,
152         identity		a string identifying the watchdog driver
162 The machine was last rebooted by the watchdog because the thermal limit was
167 A system fan monitored by the watchdog card has failed
185 The last reboot was caused by the watchdog card
195 The watchdog saw a keepalive ping since it was last queried.
199 The watchdog can do pretimeouts.
232 	WDIOS_DISABLECARD	Turn off the watchdog timer
233 	WDIOS_ENABLECARD	Turn on the watchdog timer