diff options
Diffstat (limited to 'Documentation/watchdog')
| -rw-r--r-- | Documentation/watchdog/00-INDEX | 15 | ||||
| -rw-r--r-- | Documentation/watchdog/hpwdt.txt | 95 | ||||
| -rw-r--r-- | Documentation/watchdog/pcwd-watchdog.txt | 66 | ||||
| -rw-r--r-- | Documentation/watchdog/src/.gitignore | 2 | ||||
| -rw-r--r-- | Documentation/watchdog/src/Makefile | 8 | ||||
| -rw-r--r-- | Documentation/watchdog/src/watchdog-simple.c | 24 | ||||
| -rw-r--r-- | Documentation/watchdog/src/watchdog-test.c | 72 | ||||
| -rw-r--r-- | Documentation/watchdog/watchdog-api.txt | 237 | ||||
| -rw-r--r-- | Documentation/watchdog/watchdog-parameters.txt | 395 | ||||
| -rw-r--r-- | Documentation/watchdog/wdt.txt | 50 |
10 files changed, 964 insertions, 0 deletions
diff --git a/Documentation/watchdog/00-INDEX b/Documentation/watchdog/00-INDEX new file mode 100644 index 00000000..ee994513 --- /dev/null +++ b/Documentation/watchdog/00-INDEX @@ -0,0 +1,15 @@ +00-INDEX + - this file. +hpwdt.txt + - information on the HP iLO2 NMI watchdog +pcwd-watchdog.txt + - documentation for Berkshire Products PC Watchdog ISA cards. +src/ + - directory holding watchdog related example programs. +watchdog-api.txt + - description of the Linux Watchdog driver API. +watchdog-parameters.txt + - information on driver parameters (for drivers other than + the ones that have driver-specific files here) +wdt.txt + - description of the Watchdog Timer Interfaces for Linux. diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt new file mode 100644 index 00000000..94880789 --- /dev/null +++ b/Documentation/watchdog/hpwdt.txt @@ -0,0 +1,95 @@ +Last reviewed: 06/02/2009 + + HP iLO2 NMI Watchdog Driver + NMI sourcing for iLO2 based ProLiant Servers + Documentation and Driver by + Thomas Mingarelli <thomas.mingarelli@hp.com> + + The HP iLO2 NMI Watchdog driver is a kernel module that provides basic + watchdog functionality and the added benefit of NMI sourcing. Both the + watchdog functionality and the NMI sourcing capability need to be enabled + by the user. Remember that the two modes are not dependent on one another. + A user can have the NMI sourcing without the watchdog timer and vice-versa. + + Watchdog functionality is enabled like any other common watchdog driver. That + is, an application needs to be started that kicks off the watchdog timer. A + basic application exists in the Documentation/watchdog/src directory called + watchdog-test.c. Simply compile the C file and kick it off. If the system + gets into a bad state and hangs, the HP ProLiant iLO 2 timer register will + not be updated in a timely fashion and a hardware system reset (also known as + an Automatic Server Recovery (ASR)) event will occur. + + The hpwdt driver also has four (4) module parameters. They are the following: + + soft_margin - allows the user to set the watchdog timer value + allow_kdump - allows the user to save off a kernel dump image after an NMI + nowayout - basic watchdog parameter that does not allow the timer to + be restarted or an impending ASR to be escaped. + priority - determines whether or not the hpwdt driver is first on the + die_notify list to handle NMIs or last. The default value + for this module parameter is 0 or LAST. If the user wants to + enable NMI sourcing then reload the hpwdt driver with + priority=1 (and boot with nmi_watchdog=0). + + NOTE: More information about watchdog drivers in general, including the ioctl + interface to /dev/watchdog can be found in + Documentation/watchdog/watchdog-api.txt and Documentation/IPMI.txt. + + The priority parameter was introduced due to other kernel software that relied + on handling NMIs (like oprofile). Keeping hpwdt's priority at 0 (or LAST) + enables the users of NMIs for non critical events to be work as expected. + + The NMI sourcing capability is disabled by default due to the inability to + distinguish between "NMI Watchdog Ticks" and "HW generated NMI events" in the + Linux kernel. What this means is that the hpwdt nmi handler code is called + each time the NMI signal fires off. This could amount to several thousands of + NMIs in a matter of seconds. If a user sees the Linux kernel's "dazed and + confused" message in the logs or if the system gets into a hung state, then + the hpwdt driver can be reloaded with the "priority" module parameter set + (priority=1). + + 1. If the kernel has not been booted with nmi_watchdog turned off then + edit /boot/grub/menu.lst and place the nmi_watchdog=0 at the end of the + currently booting kernel line. + 2. reboot the sever + 3. Once the system comes up perform a rmmod hpwdt + 4. insmod /lib/modules/`uname -r`/kernel/drivers/char/watchdog/hpwdt.ko priority=1 + + Now, the hpwdt can successfully receive and source the NMI and provide a log + message that details the reason for the NMI (as determined by the HP BIOS). + + Below is a list of NMIs the HP BIOS understands along with the associated + code (reason): + + No source found 00h + + Uncorrectable Memory Error 01h + + ASR NMI 1Bh + + PCI Parity Error 20h + + NMI Button Press 27h + + SB_BUS_NMI 28h + + ILO Doorbell NMI 29h + + ILO IOP NMI 2Ah + + ILO Watchdog NMI 2Bh + + Proc Throt NMI 2Ch + + Front Side Bus NMI 2Dh + + PCI Express Error 2Fh + + DMA controller NMI 30h + + Hypertransport/CSI Error 31h + + + + -- Tom Mingarelli + (thomas.mingarelli@hp.com) diff --git a/Documentation/watchdog/pcwd-watchdog.txt b/Documentation/watchdog/pcwd-watchdog.txt new file mode 100644 index 00000000..4f680523 --- /dev/null +++ b/Documentation/watchdog/pcwd-watchdog.txt @@ -0,0 +1,66 @@ +Last reviewed: 10/05/2007 + + Berkshire Products PC Watchdog Card + Support for ISA Cards Revision A and C + Documentation and Driver by Ken Hollis <kenji@bitgate.com> + + The PC Watchdog is a card that offers the same type of functionality that + the WDT card does, only it doesn't require an IRQ to run. Furthermore, + the Revision C card allows you to monitor any IO Port to automatically + trigger the card into being reset. This way you can make the card + monitor hard drive status, or anything else you need. + + The Watchdog Driver has one basic role: to talk to the card and send + signals to it so it doesn't reset your computer ... at least during + normal operation. + + The Watchdog Driver will automatically find your watchdog card, and will + attach a running driver for use with that card. After the watchdog + drivers have initialized, you can then talk to the card using a PC + Watchdog program. + + I suggest putting a "watchdog -d" before the beginning of an fsck, and + a "watchdog -e -t 1" immediately after the end of an fsck. (Remember + to run the program with an "&" to run it in the background!) + + If you want to write a program to be compatible with the PC Watchdog + driver, simply use of modify the watchdog test program: + Documentation/watchdog/src/watchdog-test.c + + + Other IOCTL functions include: + + WDIOC_GETSUPPORT + This returns the support of the card itself. This + returns in structure "PCWDS" which returns: + options = WDIOS_TEMPPANIC + (This card supports temperature) + firmware_version = xxxx + (Firmware version of the card) + + WDIOC_GETSTATUS + This returns the status of the card, with the bits of + WDIOF_* bitwise-anded into the value. (The comments + are in linux/pcwd.h) + + WDIOC_GETBOOTSTATUS + This returns the status of the card that was reported + at bootup. + + WDIOC_GETTEMP + This returns the temperature of the card. (You can also + read /dev/watchdog, which gives a temperature update + every second.) + + WDIOC_SETOPTIONS + This lets you set the options of the card. You can either + enable or disable the card this way. + + WDIOC_KEEPALIVE + This pings the card to tell it not to reset your computer. + + And that's all she wrote! + + -- Ken Hollis + (kenji@bitgate.com) + diff --git a/Documentation/watchdog/src/.gitignore b/Documentation/watchdog/src/.gitignore new file mode 100644 index 00000000..ac90997d --- /dev/null +++ b/Documentation/watchdog/src/.gitignore @@ -0,0 +1,2 @@ +watchdog-simple +watchdog-test diff --git a/Documentation/watchdog/src/Makefile b/Documentation/watchdog/src/Makefile new file mode 100644 index 00000000..40e5f46e --- /dev/null +++ b/Documentation/watchdog/src/Makefile @@ -0,0 +1,8 @@ +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o + +# List of programs to build +hostprogs-y := watchdog-simple watchdog-test + +# Tell kbuild to always build the programs +always := $(hostprogs-y) diff --git a/Documentation/watchdog/src/watchdog-simple.c b/Documentation/watchdog/src/watchdog-simple.c new file mode 100644 index 00000000..ba45803a --- /dev/null +++ b/Documentation/watchdog/src/watchdog-simple.c @@ -0,0 +1,24 @@ +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> + +int main(void) +{ + int fd = open("/dev/watchdog", O_WRONLY); + int ret = 0; + if (fd == -1) { + perror("watchdog"); + exit(EXIT_FAILURE); + } + while (1) { + ret = write(fd, "\0", 1); + if (ret != 1) { + ret = -1; + break; + } + sleep(10); + } + close(fd); + return ret; +} diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c new file mode 100644 index 00000000..63fdc34c --- /dev/null +++ b/Documentation/watchdog/src/watchdog-test.c @@ -0,0 +1,72 @@ +/* + * Watchdog Driver Test Program + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/ioctl.h> +#include <linux/types.h> +#include <linux/watchdog.h> + +int fd; + +/* + * This function simply sends an IOCTL to the driver, which in turn ticks + * the PC Watchdog card to reset its internal timer so it doesn't trigger + * a computer reset. + */ +static void keep_alive(void) +{ + int dummy; + + ioctl(fd, WDIOC_KEEPALIVE, &dummy); +} + +/* + * The main program. Run the program with "-d" to disable the card, + * or "-e" to enable the card. + */ +int main(int argc, char *argv[]) +{ + int flags; + + fd = open("/dev/watchdog", O_WRONLY); + + if (fd == -1) { + fprintf(stderr, "Watchdog device not enabled.\n"); + fflush(stderr); + exit(-1); + } + + if (argc > 1) { + if (!strncasecmp(argv[1], "-d", 2)) { + flags = WDIOS_DISABLECARD; + ioctl(fd, WDIOC_SETOPTIONS, &flags); + fprintf(stderr, "Watchdog card disabled.\n"); + fflush(stderr); + exit(0); + } else if (!strncasecmp(argv[1], "-e", 2)) { + flags = WDIOS_ENABLECARD; + ioctl(fd, WDIOC_SETOPTIONS, &flags); + fprintf(stderr, "Watchdog card enabled.\n"); + fflush(stderr); + exit(0); + } else { + fprintf(stderr, "-d to disable, -e to enable.\n"); + fprintf(stderr, "run by itself to tick the card.\n"); + fflush(stderr); + exit(0); + } + } else { + fprintf(stderr, "Watchdog Ticking Away!\n"); + fflush(stderr); + } + + while(1) { + keep_alive(); + sleep(1); + } +} diff --git a/Documentation/watchdog/watchdog-api.txt b/Documentation/watchdog/watchdog-api.txt new file mode 100644 index 00000000..eb7132ed --- /dev/null +++ b/Documentation/watchdog/watchdog-api.txt @@ -0,0 +1,237 @@ +Last reviewed: 10/05/2007 + + +The Linux Watchdog driver API. + +Copyright 2002 Christer Weingel <wingel@nano-system.com> + +Some parts of this document are copied verbatim from the sbc60xxwdt +driver which is (c) Copyright 2000 Jakob Oestergaard <jakob@ostenfeld.dk> + +This document describes the state of the Linux 2.4.18 kernel. + +Introduction: + +A Watchdog Timer (WDT) is a hardware circuit that can reset the +computer system in case of a software fault. You probably knew that +already. + +Usually a userspace daemon will notify the kernel watchdog driver via the +/dev/watchdog special device file that userspace is still alive, at +regular intervals. When such a notification occurs, the driver will +usually tell the hardware watchdog that everything is in order, and +that the watchdog should wait for yet another little while to reset +the system. If userspace fails (RAM error, kernel bug, whatever), the +notifications cease to occur, and the hardware watchdog will reset the +system (causing a reboot) after the timeout occurs. + +The Linux watchdog API is a rather ad-hoc construction and different +drivers implement different, and sometimes incompatible, parts of it. +This file is an attempt to document the existing usage and allow +future driver writers to use it as a reference. + +The simplest API: + +All drivers support the basic mode of operation, where the watchdog +activates as soon as /dev/watchdog is opened and will reboot unless +the watchdog is pinged within a certain time, this time is called the +timeout or margin. The simplest way to ping the watchdog is to write +some data to the device. So a very simple watchdog daemon would look +like this source file: see Documentation/watchdog/src/watchdog-simple.c + +A more advanced driver could for example check that a HTTP server is +still responding before doing the write call to ping the watchdog. + +When the device is closed, the watchdog is disabled, unless the "Magic +Close" feature is supported (see below). This is not always such a +good idea, since if there is a bug in the watchdog daemon and it +crashes the system will not reboot. Because of this, some of the +drivers support the configuration option "Disable watchdog shutdown on +close", CONFIG_WATCHDOG_NOWAYOUT. If it is set to Y when compiling +the kernel, there is no way of disabling the watchdog once it has been +started. So, if the watchdog daemon crashes, the system will reboot +after the timeout has passed. Watchdog devices also usually support +the nowayout module parameter so that this option can be controlled at +runtime. + +Magic Close feature: + +If a driver supports "Magic Close", the driver will not disable the +watchdog unless a specific magic character 'V' has been sent to +/dev/watchdog just before closing the file. If the userspace daemon +closes the file without sending this special character, the driver +will assume that the daemon (and userspace in general) died, and will +stop pinging the watchdog without disabling it first. This will then +cause a reboot if the watchdog is not re-opened in sufficient time. + +The ioctl API: + +All conforming drivers also support an ioctl API. + +Pinging the watchdog using an ioctl: + +All drivers that have an ioctl interface support at least one ioctl, +KEEPALIVE. This ioctl does exactly the same thing as a write to the +watchdog device, so the main loop in the above program could be +replaced with: + + while (1) { + ioctl(fd, WDIOC_KEEPALIVE, 0); + sleep(10); + } + +the argument to the ioctl is ignored. + +Setting and getting the timeout: + +For some drivers it is possible to modify the watchdog timeout on the +fly with the SETTIMEOUT ioctl, those drivers have the WDIOF_SETTIMEOUT +flag set in their option field. The argument is an integer +representing the timeout in seconds. The driver returns the real +timeout used in the same variable, and this timeout might differ from +the requested one due to limitation of the hardware. + + int timeout = 45; + ioctl(fd, WDIOC_SETTIMEOUT, &timeout); + printf("The timeout was set to %d seconds\n", timeout); + +This example might actually print "The timeout was set to 60 seconds" +if the device has a granularity of minutes for its timeout. + +Starting with the Linux 2.4.18 kernel, it is possible to query the +current timeout using the GETTIMEOUT ioctl. + + ioctl(fd, WDIOC_GETTIMEOUT, &timeout); + printf("The timeout was is %d seconds\n", timeout); + +Pretimeouts: + +Some watchdog timers can be set to have a trigger go off before the +actual time they will reset the system. This can be done with an NMI, +interrupt, or other mechanism. This allows Linux to record useful +information (like panic information and kernel coredumps) before it +resets. + + pretimeout = 10; + ioctl(fd, WDIOC_SETPRETIMEOUT, &pretimeout); + +Note that the pretimeout is the number of seconds before the time +when the timeout will go off. It is not the number of seconds until +the pretimeout. So, for instance, if you set the timeout to 60 seconds +and the pretimeout to 10 seconds, the pretimout will go of in 50 +seconds. Setting a pretimeout to zero disables it. + +There is also a get function for getting the pretimeout: + + ioctl(fd, WDIOC_GETPRETIMEOUT, &timeout); + printf("The pretimeout was is %d seconds\n", timeout); + +Not all watchdog drivers will support a pretimeout. + +Get the number of seconds before reboot: + +Some watchdog drivers have the ability to report the remaining time +before the system will reboot. The WDIOC_GETTIMELEFT is the ioctl +that returns the number of seconds before reboot. + + ioctl(fd, WDIOC_GETTIMELEFT, &timeleft); + printf("The timeout was is %d seconds\n", timeleft); + +Environmental monitoring: + +All watchdog drivers are required return more information about the system, +some do temperature, fan and power level monitoring, some can tell you +the reason for the last reboot of the system. The GETSUPPORT ioctl is +available to ask what the device can do: + + struct watchdog_info ident; + ioctl(fd, WDIOC_GETSUPPORT, &ident); + +the fields returned in the ident struct are: + + identity a string identifying the watchdog driver + firmware_version the firmware version of the card if available + options a flags describing what the device supports + +the options field can have the following bits set, and describes what +kind of information that the GET_STATUS and GET_BOOT_STATUS ioctls can +return. [FIXME -- Is this correct?] + + WDIOF_OVERHEAT Reset due to CPU overheat + +The machine was last rebooted by the watchdog because the thermal limit was +exceeded + + WDIOF_FANFAULT Fan failed + +A system fan monitored by the watchdog card has failed + + WDIOF_EXTERN1 External relay 1 + +External monitoring relay/source 1 was triggered. Controllers intended for +real world applications include external monitoring pins that will trigger +a reset. + + WDIOF_EXTERN2 External relay 2 + +External monitoring relay/source 2 was triggered + + WDIOF_POWERUNDER Power bad/power fault + +The machine is showing an undervoltage status + + WDIOF_CARDRESET Card previously reset the CPU + +The last reboot was caused by the watchdog card + + WDIOF_POWEROVER Power over voltage + +The machine is showing an overvoltage status. Note that if one level is +under and one over both bits will be set - this may seem odd but makes +sense. + + WDIOF_KEEPALIVEPING Keep alive ping reply + +The watchdog saw a keepalive ping since it was last queried. + + WDIOF_SETTIMEOUT Can set/get the timeout + +The watchdog can do pretimeouts. + + WDIOF_PRETIMEOUT Pretimeout (in seconds), get/set + + +For those drivers that return any bits set in the option field, the +GETSTATUS and GETBOOTSTATUS ioctls can be used to ask for the current +status, and the status at the last reboot, respectively. + + int flags; + ioctl(fd, WDIOC_GETSTATUS, &flags); + + or + + ioctl(fd, WDIOC_GETBOOTSTATUS, &flags); + +Note that not all devices support these two calls, and some only +support the GETBOOTSTATUS call. + +Some drivers can measure the temperature using the GETTEMP ioctl. The +returned value is the temperature in degrees fahrenheit. + + int temperature; + ioctl(fd, WDIOC_GETTEMP, &temperature); + +Finally the SETOPTIONS ioctl can be used to control some aspects of +the cards operation. + + int options = 0; + ioctl(fd, WDIOC_SETOPTIONS, &options); + +The following options are available: + + WDIOS_DISABLECARD Turn off the watchdog timer + WDIOS_ENABLECARD Turn on the watchdog timer + WDIOS_TEMPPANIC Kernel panic on temperature trip + +[FIXME -- better explanations] + diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt new file mode 100644 index 00000000..17ddd822 --- /dev/null +++ b/Documentation/watchdog/watchdog-parameters.txt @@ -0,0 +1,395 @@ +This file provides information on the module parameters of many of +the Linux watchdog drivers. Watchdog driver parameter specs should +be listed here unless the driver has its own driver-specific information +file. + + +See Documentation/kernel-parameters.txt for information on +providing kernel parameters for builtin drivers versus loadable +modules. + + +------------------------------------------------- +acquirewdt: +wdt_stop: Acquire WDT 'stop' io port (default 0x43) +wdt_start: Acquire WDT 'start' io port (default 0x443) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +advantechwdt: +wdt_stop: Advantech WDT 'stop' io port (default 0x443) +wdt_start: Advantech WDT 'start' io port (default 0x443) +timeout: Watchdog timeout in seconds. 1<= timeout <=63, default=60. +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +alim1535_wdt: +timeout: Watchdog timeout in seconds. (0 < timeout < 18000, default=60 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +alim7101_wdt: +timeout: Watchdog timeout in seconds. (1<=timeout<=3600, default=30 +use_gpio: Use the gpio watchdog (required by old cobalt boards). + default=0/off/no +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +ar7_wdt: +margin: Watchdog margin in seconds (default=60) +nowayout: Disable watchdog shutdown on close + (default=kernel config parameter) +------------------------------------------------- +at32ap700x_wdt: +timeout: Timeout value. Limited to be 1 or 2 seconds. (default=2) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +at91rm9200_wdt: +wdt_time: Watchdog time in seconds. (default=5) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +at91sam9_wdt: +heartbeat: Watchdog heartbeats in seconds. (default = 15) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +bcm47xx_wdt: +wdt_time: Watchdog time in seconds. (default=30) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +bfin_wdt: +timeout: Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default=20) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +coh901327_wdt: +margin: Watchdog margin in seconds (default 60s) +------------------------------------------------- +cpu5wdt: +port: base address of watchdog card, default is 0x91 +verbose: be verbose, default is 0 (no) +ticks: count down ticks, default is 10000 +------------------------------------------------- +cpwd: +wd0_timeout: Default watchdog0 timeout in 1/10secs +wd1_timeout: Default watchdog1 timeout in 1/10secs +wd2_timeout: Default watchdog2 timeout in 1/10secs +------------------------------------------------- +davinci_wdt: +heartbeat: Watchdog heartbeat period in seconds from 1 to 600, default 60 +------------------------------------------------- +ep93xx_wdt: +nowayout: Watchdog cannot be stopped once started +timeout: Watchdog timeout in seconds. (1<=timeout<=3600, default=TBD) +------------------------------------------------- +eurotechwdt: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +io: Eurotech WDT io port (default=0x3f0) +irq: Eurotech WDT irq (default=10) +ev: Eurotech WDT event type (default is `int') +------------------------------------------------- +gef_wdt: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +geodewdt: +timeout: Watchdog timeout in seconds. 1<= timeout <=131, default=60. +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +i6300esb: +heartbeat: Watchdog heartbeat in seconds. (1<heartbeat<2046, default=30) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +iTCO_wdt: +heartbeat: Watchdog heartbeat in seconds. + (2<heartbeat<39 (TCO v1) or 613 (TCO v2), default=30) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +iTCO_vendor_support: +vendorsupport: iTCO vendor specific support mode, default=0 (none), + 1=SuperMicro Pent3, 2=SuperMicro Pent4+, 911=Broken SMI BIOS +------------------------------------------------- +ib700wdt: +timeout: Watchdog timeout in seconds. 0<= timeout <=30, default=30. +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +ibmasr: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +imx2_wdt: +timeout: Watchdog timeout in seconds (default 60 s) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +indydog: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +iop_wdt: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +it8712f_wdt: +margin: Watchdog margin in seconds (default 60) +nowayout: Disable watchdog shutdown on close + (default=kernel config parameter) +------------------------------------------------- +it87_wdt: +nogameport: Forbid the activation of game port, default=0 +exclusive: Watchdog exclusive device open, default=1 +timeout: Watchdog timeout in seconds, default=60 +testmode: Watchdog test mode (1 = no reboot), default=0 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +ixp2000_wdt: +heartbeat: Watchdog heartbeat in seconds (default 60s) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +ixp4xx_wdt: +heartbeat: Watchdog heartbeat in seconds (default 60s) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +ks8695_wdt: +wdt_time: Watchdog time in seconds. (default=5) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +machzwd: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +action: after watchdog resets, generate: + 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI +------------------------------------------------- +max63xx_wdt: +heartbeat: Watchdog heartbeat period in seconds from 1 to 60, default 60 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +nodelay: Force selection of a timeout setting without initial delay + (max6373/74 only, default=0) +------------------------------------------------- +mixcomwd: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +mpc8xxx_wdt: +timeout: Watchdog timeout in ticks. (0<timeout<65536, default=65535) +reset: Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +mpcore_wdt: +mpcore_margin: MPcore timer margin in seconds. + (0 < mpcore_margin < 65536, default=60) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +mpcore_noboot: MPcore watchdog action, set to 1 to ignore reboots, + 0 to reboot (default=0 +------------------------------------------------- +mv64x60_wdt: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +nuc900_wdt: +heartbeat: Watchdog heartbeats in seconds. + (default = 15) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +omap_wdt: +timer_margin: initial watchdog timeout (in seconds) +------------------------------------------------- +orion_wdt: +heartbeat: Initial watchdog heartbeat in seconds +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +pc87413_wdt: +io: pc87413 WDT I/O port (default: io). +timeout: Watchdog timeout in minutes (default=timeout). +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +pika_wdt: +heartbeat: Watchdog heartbeats in seconds. (default = 15) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +pnx4008_wdt: +heartbeat: Watchdog heartbeat period in seconds from 1 to 60, default 19 +nowayout: Set to 1 to keep watchdog running after device release +------------------------------------------------- +pnx833x_wdt: +timeout: Watchdog timeout in Mhz. (68Mhz clock), default=2040000000 (30 seconds) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +start_enabled: Watchdog is started on module insertion (default=1) +------------------------------------------------- +rc32434_wdt: +timeout: Watchdog timeout value, in seconds (default=20) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +riowd: +riowd_timeout: Watchdog timeout in minutes (default=1) +------------------------------------------------- +s3c2410_wdt: +tmr_margin: Watchdog tmr_margin in seconds. (default=15) +tmr_atboot: Watchdog is started at boot time if set to 1, default=0 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +soft_noboot: Watchdog action, set to 1 to ignore reboots, 0 to reboot +debug: Watchdog debug, set to >1 for debug, (default 0) +------------------------------------------------- +sa1100_wdt: +margin: Watchdog margin in seconds (default 60s) +------------------------------------------------- +sb_wdog: +timeout: Watchdog timeout in microseconds (max/default 8388607 or 8.3ish secs) +------------------------------------------------- +sbc60xxwdt: +wdt_stop: SBC60xx WDT 'stop' io port (default 0x45) +wdt_start: SBC60xx WDT 'start' io port (default 0x443) +timeout: Watchdog timeout in seconds. (1<=timeout<=3600, default=30) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +sbc7240_wdt: +timeout: Watchdog timeout in seconds. (1<=timeout<=255, default=30) +nowayout: Disable watchdog when closing device file +------------------------------------------------- +sbc8360: +timeout: Index into timeout table (0-63) (default=27 (60s)) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +sbc_epx_c3: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +sbc_fitpc2_wdt: +margin: Watchdog margin in seconds (default 60s) +nowayout: Watchdog cannot be stopped once started +------------------------------------------------- +sc1200wdt: +isapnp: When set to 0 driver ISA PnP support will be disabled (default=1) +io: io port +timeout: range is 0-255 minutes, default is 1 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +sc520_wdt: +timeout: Watchdog timeout in seconds. (1 <= timeout <= 3600, default=30) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +sch311x_wdt: +force_id: Override the detected device ID +therm_trip: Should a ThermTrip trigger the reset generator +timeout: Watchdog timeout in seconds. 1<= timeout <=15300, default=60 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +scx200_wdt: +margin: Watchdog margin in seconds +nowayout: Disable watchdog shutdown on close +------------------------------------------------- +shwdt: +clock_division_ratio: Clock division ratio. Valid ranges are from 0x5 (1.31ms) + to 0x7 (5.25ms). (default=7) +heartbeat: Watchdog heartbeat in seconds. (1 <= heartbeat <= 3600, default=30 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +smsc37b787_wdt: +timeout: range is 1-255 units, default is 60 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +softdog: +soft_margin: Watchdog soft_margin in seconds. + (0 < soft_margin < 65536, default=60) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +soft_noboot: Softdog action, set to 1 to ignore reboots, 0 to reboot + (default=0) +------------------------------------------------- +stmp3xxx_wdt: +heartbeat: Watchdog heartbeat period in seconds from 1 to 4194304, default 19 +------------------------------------------------- +ts72xx_wdt: +timeout: Watchdog timeout in seconds. (1 <= timeout <= 8, default=8) +nowayout: Disable watchdog shutdown on close +------------------------------------------------- +twl4030_wdt: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +txx9wdt: +timeout: Watchdog timeout in seconds. (0<timeout<N, default=60) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +w83627hf_wdt: +wdt_io: w83627hf/thf WDT io port (default 0x2E) +timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60. +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +w83697hf_wdt: +wdt_io: w83697hf/hg WDT io port (default 0x2e, 0 = autodetect) +timeout: Watchdog timeout in seconds. 1<= timeout <=255 (default=60) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +early_disable: Watchdog gets disabled at boot time (default=1) +------------------------------------------------- +w83697ug_wdt: +wdt_io: w83697ug/uf WDT io port (default 0x2e) +timeout: Watchdog timeout in seconds. 1<= timeout <=255 (default=60) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +w83877f_wdt: +timeout: Watchdog timeout in seconds. (1<=timeout<=3600, default=30) +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +w83977f_wdt: +timeout: Watchdog timeout in seconds (15..7635), default=45) +testmode: Watchdog testmode (1 = no reboot), default=0 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +wafer5823wdt: +timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60. +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +wdt285: +soft_margin: Watchdog timeout in seconds (default=60) +------------------------------------------------- +wdt977: +timeout: Watchdog timeout in seconds (60..15300, default=60) +testmode: Watchdog testmode (1 = no reboot), default=0 +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +wm831x_wdt: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- +wm8350_wdt: +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- diff --git a/Documentation/watchdog/wdt.txt b/Documentation/watchdog/wdt.txt new file mode 100644 index 00000000..061c2e35 --- /dev/null +++ b/Documentation/watchdog/wdt.txt @@ -0,0 +1,50 @@ +Last Reviewed: 10/05/2007 + + WDT Watchdog Timer Interfaces For The Linux Operating System + Alan Cox <alan@lxorguk.ukuu.org.uk> + + ICS WDT501-P + ICS WDT501-P (no fan tachometer) + ICS WDT500-P + +All the interfaces provide /dev/watchdog, which when open must be written +to within a timeout or the machine will reboot. Each write delays the reboot +time another timeout. In the case of the software watchdog the ability to +reboot will depend on the state of the machines and interrupts. The hardware +boards physically pull the machine down off their own onboard timers and +will reboot from almost anything. + +A second temperature monitoring interface is available on the WDT501P cards. +This provides /dev/temperature. This is the machine internal temperature in +degrees Fahrenheit. Each read returns a single byte giving the temperature. + +The third interface logs kernel messages on additional alert events. + +The ICS ISA-bus wdt card cannot be safely probed for. Instead you need to +pass IO address and IRQ boot parameters. E.g.: + wdt.io=0x240 wdt.irq=11 + +Other "wdt" driver parameters are: + heartbeat Watchdog heartbeat in seconds (default 60) + nowayout Watchdog cannot be stopped once started (kernel + build parameter) + tachometer WDT501-P Fan Tachometer support (0=disable, default=0) + type WDT501-P Card type (500 or 501, default=500) + +Features +-------- + WDT501P WDT500P +Reboot Timer X X +External Reboot X X +I/O Port Monitor o o +Temperature X o +Fan Speed X o +Power Under X o +Power Over X o +Overheat X o + +The external event interfaces on the WDT boards are not currently supported. +Minor numbers are however allocated for it. + + +Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c |