kernel.git/Documentation/watchdog, branch linux-4.5.y

Add sun4v_wdt watchdog driver

2016-01-31T19:06:24Z

This driver adds sparc hypervisor watchdog support. The default timeout is 60 seconds and the range is between 1 and 31536000 seconds. Both watchdog-resolution and watchdog-max-timeout MD properties settings are supported. Signed-off-by: Wim Coekaerts Reviewed-by: Julian Calaby Reviewed-by: Guenter Roeck Signed-off-by: David S. Miller

watchdog: Drop pointer to watchdog device from struct watchdog_device

2016-01-11T20:53:59Z

The lifetime of the watchdog device pointer is different from the lifetime of its character device. Remove it entirely to avoid race conditions. Signed-off-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck

watchdog: Add support for creating driver specific sysfs attributes

2016-01-11T20:53:57Z

The Zodiac watchdog driver attaches additional sysfs attributes to the watchdog device. This has a number of problems: The watchdog device lifetime differs from the driver lifetime, and the device structure should therefore not be accessed from drivers. Also, creating sysfs attributes after driver registration results in a potential race condition if user space expects the attributes to exist but they don't exist yet. Add support for creating driver specific sysfs attributes to the watchdog core to solve the problems. Signed-off-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck

watchdog: Separate and maintain variables based on variable lifetime

2015-12-29T19:36:03Z

All variables required by the watchdog core to manage a watchdog are currently stored in struct watchdog_device. The lifetime of those variables is determined by the watchdog driver. However, the lifetime of variables used by the watchdog core differs from the lifetime of struct watchdog_device. To remedy this situation, watchdog drivers can implement ref and unref callbacks, to be used by the watchdog core to lock struct watchdog_device in memory. While this solves the immediate problem, it depends on watchdog drivers to actually implement the ref/unref callbacks. This is error prone, often not implemented in the first place, or not implemented correctly. To solve the problem without requiring driver support, split the variables in struct watchdog_device into two data structures - one for variables associated with the watchdog driver, one for variables associated with the watchdog core. With this approach, the watchdog core can keep track of its variable lifetime and no longer depends on ref/unref callbacks in the driver. As a side effect, some of the variables originally in struct watchdog_driver are now private to the watchdog core and no longer visible in watchdog drivers. As a side effect of the changes made, an ioctl will now always fail with -ENODEV after a watchdog device was unregistered with the character device still open. Previously, it would only fail with -ENODEV in some situations. Also, ioctl operations are now atomic from driver perspective. With this change, it is now guaranteed that the driver will not unregister a watchdog between a timeout change and the subsequent ping. The 'ref' and 'unref' callbacks in struct watchdog_driver are no longer used and marked as deprecated. Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck

watchdog: core: add reboot notifier support

2015-12-13T14:55:51Z

Many watchdog drivers register a reboot notifier in order to stop the watchdog on system reboot. Thus we can factorize this code in the watchdog core. For that purpose, a new notifier block is added in watchdog_device for internal use only, as well as a new watchdog_stop_on_reboot helper function. If this helper is called, watchdog core registers the related notifier block and will stop the watchdog when SYS_HALT or SYS_DOWN is received. Since this operation can be critical on some platforms, abort the device registration if the reboot notifier registration fails. Suggested-by: Vivien Didelot Signed-off-by: Damien Riegel Reviewed-by: Vivien Didelot Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck

watchdog: core: add restart handler support

2015-12-13T14:27:10Z

Many watchdog drivers implement the same code to register a restart handler. This patch provides a generic way to set such a function. The patch adds a new restart watchdog operation. If a restart priority greater than 0 is needed, the driver can call watchdog_set_restart_priority to set it. Suggested-by: Vivien Didelot Signed-off-by: Damien Riegel Reviewed-by: Guenter Roeck Reviewed-by: Vivien Didelot Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck

Documentation/watchdog: add timeout and ping rate control to watchdog-test.c

2015-09-09T19:33:36Z

The watchdog test program is much more useful if it can configure the timeout value and ping rate. This will allow you to test actual timeouts. Adds the -t parameter to set the timeout value (in seconds), and -p to set the ping rate (number of seconds between pings). Signed-off-by: Timur Tabi Reviewed-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck

watchdog: omap_wdt: early_enable module parameter

2015-07-01T14:43:17Z

Add a early_enable module parameter to the omap_wdt that starts the watchdog on module insertion. The default value is 0 which does not start the watchdog - which also does not change the behavior if the parameter is not given. Signed-off-by: Lars Poeschel Reviewed-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck

watchdog: watchdog_core: Add watchdog registration deferral mechanism

2015-06-29T09:51:06Z

Currently, watchdog subsystem require the misc subsystem to register a watchdog. This may not be the case in case of an early registration of a watchdog, which can be required when the watchdog cannot be disabled. This patch introduces a deferral mechanism to remove this requirement. Signed-off-by: Jean-Baptiste Theou Reviewed-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck

watchdog: docs: omap_wdt also understands nowayout

2015-06-22T13:54:36Z

The omap_wdt kernel driver also understands the nowayout module parameter. This updates the watchdog-parameters.txt to reflect this fact. Signed-off-by: Lars Poeschel Reviewed-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck