Subject: [PATCH v1 1/2] watchdog: add WDIOC_SETPRETIMEOUT and WDIOC_GETPRETIMEOUT

From: [email-masked] (Guenter Roeck)
Date: Mon, 2 Nov 2015 20:59:21 -0800

On 11/02/2015 08:47 PM, Robin Gong wrote:
> On Mon, Nov 02, 2015 at 08:04:20PM -0800, Guenter Roeck wrote:
>> On 11/02/2015 07:29 PM, Robin Gong wrote:
>>> Since the watchdog common framework centrialize the IOCTL interfaces of
>>> device driver now, the SETPRETIMEOUT and GETPRETIMEOUT need to be added
>>> in the common code.
>>>
>>> Signed-off-by: Robin Gong <[email-masked]>
>>> ---
>>>   drivers/watchdog/watchdog_dev.c | 38 ++++++++++++++++++++++++++++++++++++++
>>>   include/linux/watchdog.h        |  9 +++++++++
>>>   2 files changed, 47 insertions(+)
>>>
>>> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
>>> index 6aaefba..02632fe 100644
>>> --- a/drivers/watchdog/watchdog_dev.c
>>> +++ b/drivers/watchdog/watchdog_dev.c
>>> @@ -218,6 +218,37 @@ out_timeout:
>>>   }
>>>
>>>   /*
>>> + *	watchdog_set_pretimeout: set the watchdog timer pretimeout
>>> + *	@wddev: the watchdog device to set the timeout for
>>> + *	@timeout: pretimeout to set in seconds
>>> + */
>>> +
>>> +static int watchdog_set_pretimeout(struct watchdog_device *wddev,
>>> +							unsigned int timeout)
>>
>> Please align with "(".
> Will fix in v2.
>>
>>> +{
>>> +	int err;
>>> +
>>> +	if ((wddev->ops->set_pretimeout == NULL) ||
>>
>> Unnecessary ( ), and "== NULL" is unnecessary as well.
>>
> why? It's useful if other device driver didn't implement set_pretimeout.

	if (!wddev->ops->set_pretimeout ||

>>> +	    !(wddev->info->options & WDIOF_PRETIMEOUT))
>>> +		return -EOPNOTSUPP;
>>> +	if (watchdog_pretimeout_invalid(wddev, timeout))
>>> +		return -EINVAL;
>>> +
>>> +	mutex_lock(&wddev->lock);
>>> +
>>> +	if (test_bit(WDOG_UNREGISTERED, &wddev->status)) {
>>> +		err = -ENODEV;
>>> +		goto out_timeout;
>>> +	}
>>> +
>>> +	err = wddev->ops->set_pretimeout(wddev, timeout);
>>> +
>>> +out_timeout:
>>> +	mutex_unlock(&wddev->lock);
>>> +	return err;
>>> +}
>>> +
>>> +/*
>>>    *	watchdog_get_timeleft: wrapper to get the time left before a reboot
>>>    *	@wddev: the watchdog device to get the remaining time from
>>>    *	@timeleft: the time that's left
>>> @@ -393,6 +424,13 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
>>>   		if (err)
>>>   			return err;
>>>   		return put_user(val, p);
>>> +	case WDIOC_SETPRETIMEOUT:
>>> +		if (get_user(val, p))
>>> +			return -EFAULT;
>>> +		err = watchdog_set_pretimeout(wdd, val);
>>> +		return err;
>>
>> 		return watchdog_set_pretimeout(wdd, val);
>>
>>> +	case WDIOC_GETPRETIMEOUT:
>>> +		return put_user(wdd->pretimeout, p);
>>>   	default:
>>>   		return -ENOTTY;
>>>   	}
>>> diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
>>> index d74a0e9..6ddb2d6 100644
>>> --- a/include/linux/watchdog.h
>>> +++ b/include/linux/watchdog.h
>>> @@ -25,6 +25,7 @@ struct watchdog_device;
>>>    * @ping:	The routine that sends a keepalive ping to the watchdog device.
>>>    * @status:	The routine that shows the status of the watchdog device.
>>>    * @set_timeout:The routine for setting the watchdog devices timeout value.
>>> + * @set_pretimeout:The routine for setting the watchdog devices pretimeout.
>>>    * @get_timeleft:The routine that get's the time that's left before a reset.
>>>    * @ref:	The ref operation for dyn. allocated watchdog_device structs
>>>    * @unref:	The unref operation for dyn. allocated watchdog_device structs
>>> @@ -44,6 +45,7 @@ struct watchdog_ops {
>>>   	int (*ping)(struct watchdog_device *);
>>>   	unsigned int (*status)(struct watchdog_device *);
>>>   	int (*set_timeout)(struct watchdog_device *, unsigned int);
>>> +	int (*set_pretimeout)(struct watchdog_device *, unsigned int);
>>>   	unsigned int (*get_timeleft)(struct watchdog_device *);
>>>   	void (*ref)(struct watchdog_device *);
>>>   	void (*unref)(struct watchdog_device *);
>>> @@ -86,6 +88,7 @@ struct watchdog_device {
>>>   	const struct watchdog_ops *ops;
>>>   	unsigned int bootstatus;
>>>   	unsigned int timeout;
>>> +	unsigned int pretimeout;
>>
>> Description (further below) missing.
>>
> I describe it in the ahead of this structure as the above.
>>>   	unsigned int min_timeout;
>>>   	unsigned int max_timeout;
>>>   	void *driver_data;
>>> @@ -123,6 +126,12 @@ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigne
>>>   		(t < wdd->min_timeout || t > wdd->max_timeout));
>>>   }
>>>
>>> +/* Use the following function to check if a pretimeout value is invalid */
>>> +static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd, unsigned int t)
>>
>> Please fix checkpatch warnings.
>>
> You mean over 80 characters? Will fix in v2.
>>> +{
>>> +	return ((wdd->timeout != 0) && (t >= wdd->timeout));
>>
>> Unnecessary ( ), and "!= 0" is unnecessary.
>>
> I think t >= wdd->timeout is need, since it's a pre-timeout.

	return wdd->timeout && t >= wdd->timeout;

>>> +}
>>> +
>>>   /* Use the following functions to manipulate watchdog driver specific data */
>>>   static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data)
>>>   {
>>>
>>
>