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path: root/drivers/watchdog/watchdog_dev.c
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2013-07-11watchdog: core: don't try to stop device if not runningHector Palacios1-2/+4
A watchdog device may be stopped from userspace using WDIOC_SETOPTIONS ioctl and flag WDIOS_DISABLECARD. If the device is closed after this operation, watchdog_release() is called and status bits checked for stopping it. Besides, if the device has not been unregistered a critical message "watchdog did not stop!" is printed, although the ioctl may have successfully stopped it already. Without the patch a user application sample code like this will successfully stop the watchdog, but the kernel will output the message "watchdog did not stop!": wd_fd = open("/dev/watchdog", O_RDWR); flags = WDIOS_DISABLECARD; ioctl(wd_fd, WDIOC_SETOPTIONS, &flags); close(wd_fd); Signed-off-by: Hector Palacios <hector.palacios@digi.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-05-09watchdog: Fix race condition in registration codeGuenter Roeck1-1/+2
A race condition exists when registering the first watchdog device. Sequence of events: - watchdog_register_device calls watchdog_dev_register - watchdog_dev_register creates the watchdog misc device by calling misc_register. At that time, the matching character device (/dev/watchdog0) does not yet exist, and old_wdd is not set either. - Userspace gets an event and opens /dev/watchdog - watchdog_open is called and sets wdd = old_wdd, which is still NULL, and tries to dereference it. This causes the kernel to panic. Seen with systemd trying to open /dev/watchdog immediately after it was created. Reported-by: Arkadiusz Miskiewicz <arekm@maven.pl> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Arkadiusz Miskiewicz <arekm@maven.pl> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-03-01watchdog: core: dt: add support for the timeout-sec dt propertyFabio Porcedda1-2/+1
Add support for watchdog drivers to initialize/set the timeout field of the watchdog_device structure. The timeout field is initialised either with the module timeout parameter value (if valid) or with the timeout-sec dt property (if valid). If both are invalid the initial value is unchanged. Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-06-28watchdog: core: fix WDIOC_GETSTATUS return valueWim Van Sebroeck1-1/+1
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 <wim@iguana.be>
2012-05-30watchdog: Add support for dynamically allocated watchdog_device structsHans de Goede1-1/+54
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 <hdegoede@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: Add Locking supportHans de Goede1-0/+21
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 <hdegoede@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: watchdog_dev: Rewrite wrapper codeHans de Goede1-40/+130
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 <hdegoede@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: use dev_ functionsAlan Cox1-3/+2
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 <alan@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: create all the proper device filesAlan Cox1-0/+1
Create the watchdog class and it's associated devices. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: Add multiple device supportAlan Cox1-45/+82
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 <alan@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: correct the name of the watchdog_core inlude fileWim Van Sebroeck1-1/+1
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 <wim@iguana.be>
2012-05-30watchdog: Add watchdog_active() routineViresh Kumar1-3/+3
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 <viresh.kumar@st.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30watchdog: watchdog_dev: include private header to pickup global symbol ↵H Hartley Sweeten1-0/+2
prototypes 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 <hsweeten@visionengravers.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27watchdog: Add support for WDIOC_GETTIMELEFT IOCTL in watchdog coreViresh Kumar1-0/+5
This patch adds support for WDIOC_GETTIMELEFT IOCTL in watchdog core. So, there is another function pointer added to struct watchdog_ops, which can be passed by drivers to support this IOCTL. Related documentation is updated too. Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27watchdog: watchdog_dev: Let the driver update the timeout field on ↵Hans de Goede1-1/+0
set_timeout success When a set_timeout operation succeeds this does not necessarily mean that the exact timeout requested has been achieved, because the watchdog does not necessarily have a 1 second resolution. So rather then have the core set the timeout member of the watchdog_device struct to the exact requested value, instead the driver should set it to the actually achieved timeout value. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27watchdog: Use pr_<fmt> and pr_<level>Joe Perches1-5/+5
Use the current logging styles. Make sure all output has a prefix. Add missing newlines. Remove now unnecessary PFX, NAME, and miscellaneous other #defines. Coalesce formats. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2011-09-20watchdog: WatchDog Timer Driver Core - use passed watchdog_deviceH Hartley Sweeten1-7/+7
Use the passed watchdog_device instead of the static global variable when testing and setting the status in watchdog_ping, watchdog_start, and watchdog_stop. Note that the callers of these functions are actually passing the static global variable. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2011-07-28watchdog: WatchDog Timer Driver Core - Add minimum and max timeoutWim Van Sebroeck1-0/+3
Add min_timeout (minimum timeout) and max_timeout values so that the framework can check if the new timeout value is between the minimum and maximum timeout values. If both values are 0, then the framework will leave the check for the watchdog device driver itself. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add ioctl callWim Van Sebroeck1-0/+6
Add support for extra ioctl calls by adding a ioctl watchdog operation. This operation will be called before we do our own handling of ioctl commands. This way we can override the internal ioctl command handling and we can also add extra ioctl commands. The ioctl watchdog operation should return the appropriate error codes or -ENOIOCTLCMD if the ioctl command should be handled through the internal ioctl handling of the framework. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add nowayout featureWim Van Sebroeck1-5/+13
Add support for the nowayout feature to the WatchDog Timer Driver Core framework. This feature prevents the watchdog timer from being stopped. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add Magic Close featureWim Van Sebroeck1-3/+24
Add support for the Magic Close feature to the WatchDog Timer Driver Core framework. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add WDIOC_SETTIMEOUT and ↵Wim Van Sebroeck1-0/+20
WDIOC_GETTIMEOUT ioctl This part add's the WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctl functionality to the WatchDog Timer Driver Core framework. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add WDIOC_SETOPTIONS ioctlWim Van Sebroeck1-7/+72
This part add's the WDIOC_SETOPTIONS ioctl functionality to the WatchDog Timer Driver Core framework. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add WDIOC_KEEPALIVE ioctlWim Van Sebroeck1-0/+5
This part add's the WDIOC_KEEPALIVE ioctl functionality to the WatchDog Timer Driver Core framework. Please note that the WDIOF_KEEPALIVEPING bit has to be set in the watchdog_info options field. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add basic ioctl functionalityWim Van Sebroeck1-0/+32
This part add's the basic ioctl functionality to the WatchDog Timer Driver Core framework. The supported ioctl call's are: WDIOC_GETSUPPORT WDIOC_GETSTATUS WDIOC_GETBOOTSTATUS Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28watchdog: WatchDog Timer Driver Core - Add basic frameworkWim Van Sebroeck1-0/+235
The WatchDog Timer Driver Core is a framework that contains the common code for all watchdog-driver's. It also introduces a watchdog device structure and the operations that go with it. This is the introduction of this framework. This part supports the minimal watchdog userspace API (or with other words: the functionality to use /dev/watchdog's open, release and write functionality as defined in the simplest watchdog API). Extra functionality will follow in the next set of patches. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>