Lines Matching refs:watchdog

23 Usually a userspace daemon will notify the kernel watchdog driver via the
24 /dev/watchdog special device file that userspace is still alive, at
26 usually tell the hardware watchdog that everything is in order, and
27 that the watchdog should wait for yet another little while to reset
29 notifications cease to occur, and the hardware watchdog will reset the
32 The Linux watchdog API is a rather ad-hoc construction and different
40 All drivers support the basic mode of operation, where the watchdog
41 activates as soon as /dev/watchdog is opened and will reboot unless
42 the watchdog is pinged within a certain time, this time is called the
43 timeout or margin.  The simplest way to ping the watchdog is to write
44 some data to the device.  So a very simple watchdog daemon would look
45 like this source file:  see samples/watchdog/watchdog-simple.c
48 still responding before doing the write call to ping the watchdog.
50 When the device is closed, the watchdog is disabled, unless the "Magic
52 good idea, since if there is a bug in the watchdog daemon and it
54 drivers support the configuration option "Disable watchdog shutdown on
56 the kernel, there is no way of disabling the watchdog once it has been
57 started.  So, if the watchdog daemon crashes, the system will reboot
66 watchdog unless a specific magic character 'V' has been sent to
67 /dev/watchdog just before closing the file.  If the userspace daemon
70 stop pinging the watchdog without disabling it first.  This will then
71 cause a reboot if the watchdog is not re-opened in sufficient time.
78 Pinging the watchdog using an ioctl:
82 watchdog device, so the main loop in the above program could be
95 For some drivers it is possible to modify the watchdog timeout on the
118 Some watchdog timers can be set to have a trigger go off before the
138 Not all watchdog drivers will support a pretimeout.
143 Some watchdog drivers have the ability to report the remaining time
153 All watchdog drivers are required return more information about the system,
164         identity		a string identifying the watchdog driver
177 The machine was last rebooted by the watchdog because the thermal limit was
184 A system fan monitored by the watchdog card has failed
210 The last reboot was caused by the watchdog card
224 The watchdog saw a keepalive ping since it was last queried.
230 The watchdog can do pretimeouts.
266 	WDIOS_DISABLECARD	Turn off the watchdog timer
267 	WDIOS_ENABLECARD	Turn on the watchdog timer