On 02/02/2012 06:48 PM, Wolfram Sang wrote:
> Some watchdogs rewrite the timer on every ping, so they don't need a specific
> set_timeout callback. Allow the callback to be empty for such devices.
>
> Signed-off-by: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
> ---
> .../watchdog/convert_drivers_to_kernel_api.txt | 10 ++++++----
> Documentation/watchdog/watchdog-kernel-api.txt | 4 +++-
> drivers/watchdog/watchdog_dev.c | 11 ++++++-----
> 3 files changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/watchdog/convert_drivers_to_kernel_api.txt b/Documentation/watchdog/convert_drivers_to_kernel_api.txt
> index be8119b..25647a3 100644
> --- a/Documentation/watchdog/convert_drivers_to_kernel_api.txt
> +++ b/Documentation/watchdog/convert_drivers_to_kernel_api.txt
> @@ -51,10 +51,12 @@ Here is a overview of the functions and probably needed actions:
> set
>
> WDIOC_SETTIMEOUT:
> - Options in watchdog_info need to have WDIOF_SETTIMEOUT set
> - and a set_timeout-callback has to be defined. The core will also
> - do limit-checking, if min_timeout and max_timeout in the watchdog
> - device are set. All is optional.
> + Options in watchdog_info need to have WDIOF_SETTIMEOUT set. The core
> + will also do limit-checking, if min_timeout and max_timeout in the
> + watchdog device are set. By default, the timeout variable of the
> + watchdog device will simply get updated. Additionally, a
> + set_timeout-callback can be defined if further actions are needed
> + (e.g. hardware setup, more advanced checks). All is optional.
>
> WDIOC_GETTIMEOUT:
> No preparations needed
> diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
> index 4b93c28..dcf1cfe 100644
> --- a/Documentation/watchdog/watchdog-kernel-api.txt
> +++ b/Documentation/watchdog/watchdog-kernel-api.txt
> @@ -121,7 +121,9 @@ they are supported. These optional routines/operations are:
> value of the watchdog_device will be changed to the value that was just used
> to re-program the watchdog timer device.
> (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
> - watchdog's info structure).
> + watchdog's info structure. If it is set, and no set_timeout function is
> + provided, only the update of the timeout value will happen. This is enough
> + if the ping of the watchdog will rewrite the timer anyway.)
> * ioctl: if this routine is present then it will be called first before we do
> our own internal ioctl call handling. This routine should return -ENOIOCTLCMD
> if a command is not supported. The parameters that are passed to the ioctl
> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
> index 1199da0..ec224b4 100644
> --- a/drivers/watchdog/watchdog_dev.c
> +++ b/drivers/watchdog/watchdog_dev.c
> @@ -215,17 +215,18 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
> watchdog_ping(wdd);
> return 0;
> case WDIOC_SETTIMEOUT:
> - if ((wdd->ops->set_timeout == NULL) ||
> - !(wdd->info->options & WDIOF_SETTIMEOUT))
> + if (!(wdd->info->options & WDIOF_SETTIMEOUT))
> return -EOPNOTSUPP;
> if (get_user(val, p))
> return -EFAULT;
> if ((wdd->max_timeout != 0) &&
> (val < wdd->min_timeout || val > wdd->max_timeout))
> return -EINVAL;
> - err = wdd->ops->set_timeout(wdd, val);
> - if (err < 0)
> - return err;
> + if (wdd->ops->set_timeout) {
> + err = wdd->ops->set_timeout(wdd, val);
> + if (err < 0)
> + return err;
> + }
> wdd->timeout = val;
> /* If the watchdog is active then we send a keepalive ping
> * to make sure that the watchdog keep's running (and if
Tested-by: Roland Stigge <stigge@xxxxxxxxx>
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