From ef90174f821041313d42d99c1c8b35a3af64a910 Mon Sep 17 00:00:00 2001 From: Jean-Baptiste Theou Date: Tue, 9 Jun 2015 09:55:02 -0700 Subject: watchdog: watchdog_core: Add watchdog registration deferral mechanism 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 --- Documentation/watchdog/watchdog-kernel-api.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation') diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index a0438f3957ca..d8b0d3367706 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -36,6 +36,10 @@ The watchdog_unregister_device routine deregisters a registered watchdog timer device. The parameter of this routine is the pointer to the registered watchdog_device structure. +The watchdog subsystem includes an registration deferral mechanism, +which allows you to register an watchdog as early as you wish during +the boot process. + The watchdog device structure looks like this: struct watchdog_device { @@ -52,6 +56,7 @@ struct watchdog_device { void *driver_data; struct mutex lock; unsigned long status; + struct list_head deferred; }; It contains following fields: @@ -80,6 +85,8 @@ It contains following fields: information about the status of the device (Like: is the watchdog timer running/active, is the nowayout bit set, is the device opened via the /dev/watchdog interface or not, ...). +* deferred: entry in wtd_deferred_reg_list which is used to + register early initialized watchdogs. The list of watchdog operations is defined as: -- cgit v1.2.3