kernel.git/drivers/watchdog/watchdog_dev.c, branch linux-3.7.y

watchdog: core: fix WDIOC_GETSTATUS return value

2012-06-28T18:40:56Z

In commit 7a87982420e5e126bfefeb42232d1fd92052794e we added a wrapper for the WDIOC_GETSTATUS ioctl call. The code results however in a different behaviour: it returns an error if the driver doesn't support the status operation. This is not according to the API that says that when we don't support the status operation, that we just should return a 0 value. Only when the device isn't there anymore, we should return an error. Signed-off-by: Wim Van Sebroeck

watchdog: Add support for dynamically allocated watchdog_device structs

2012-05-30T05:55:31Z

If a driver's watchdog_device struct is part of a dynamically allocated struct (which it often will be), merely locking the module is not enough, even with a drivers module locked, the driver can be unbound from the device, examples: 1) The root user can unbind it through sysfd 2) The i2c bus master driver being unloaded for an i2c watchdog I will gladly admit that these are corner cases, but we still need to handle them correctly. The fix for this consists of 2 parts: 1) Add ref / unref operations, so that the driver can refcount the struct holding the watchdog_device struct and delay freeing it until any open filehandles referring to it are closed 2) Most driver operations will do IO on the device and the driver should not do any IO on the device after it has been unbound. Rather then letting each driver deal with this internally, it is better to ensure at the watchdog core level that no operations (other then unref) will get called after the driver has called watchdog_unregister_device(). This actually is the bulk of this patch. Signed-off-by: Hans de Goede Signed-off-by: Wim Van Sebroeck

watchdog: Add Locking support

2012-05-30T05:55:23Z

This patch fixes some potential multithreading issues, despite only allowing one process to open the /dev/watchdog device, we can still get called multiple times at the same time, since a program could be using thread, or could share the fd after a fork. This causes 2 potential problems: 1) watchdog_start / open do an unlocked test_n_set / test_n_clear, if these 2 race, the watchdog could be stopped while the active bit indicates it is running or visa versa. 2) Most watchdog_dev drivers probably assume that only one watchdog-op will get called at a time, this is not necessary true atm. Signed-off-by: Hans de Goede Signed-off-by: Wim Van Sebroeck

watchdog: watchdog_dev: Rewrite wrapper code

2012-05-30T05:55:17Z

Rewrite and extend the wrapper code so that we can easily introduce locking (this to be able to prevent potential multithreading issues). Signed-off-by: Hans de Goede Signed-off-by: Wim Van Sebroeck

watchdog: use dev_ functions

2012-05-30T05:54:57Z

While they are registered all our watchdogs now have a valid device object so we can in turn use that to report problems nicely. Signed-off-by: Alan Cox Signed-off-by: Hans de Goede Signed-off-by: Wim Van Sebroeck

watchdog: create all the proper device files

2012-05-30T05:54:46Z

Create the watchdog class and it's associated devices. Signed-off-by: Alan Cox Signed-off-by: Hans de Goede Signed-off-by: Wim Van Sebroeck

watchdog: Add multiple device support

2012-05-30T05:54:25Z

We keep the old /dev/watchdog interface file for the first watchdog via miscdev. This is basically a cut and paste of the relevant interface code from the rtc driver layer tweaked for watchdog. Revised to fix problems noted by Hans de Goede Signed-off-by: Alan Cox Signed-off-by: Hans de Goede Signed-off-by: Tomas Winkler Signed-off-by: Wim Van Sebroeck

watchdog: correct the name of the watchdog_core inlude file

2012-05-30T05:54:03Z

The watchdog_core include file should have been named watchdog_core.h and not watchdog_dev.h . Correct this. Signed-off-by: Wim Van Sebroeck

watchdog: Add watchdog_active() routine

2012-05-30T05:53:46Z

Some watchdog may need to check if watchdog is ACTIVE or not, for example in their suspend/resume hooks. This patch adds this routine and changes the core drivers to use it. Signed-off-by: Viresh Kumar Signed-off-by: Wim Van Sebroeck

watchdog: watchdog_dev: include private header to pickup global symbol prototypes

2012-05-30T05:53:28Z

Include the private watchdog_dev.h header to pickup the prototypes for the watchdog_dev_register/unregister functions. This quiets the following sparse warnings: warning: symbol 'watchdog_dev_register' was not declared. Should it be static? warning: symbol 'watchdog_dev_unregister' was not declared. Should it be static? Signed-off-by: H Hartley Sweeten Signed-off-by: Wim Van Sebroeck