Re: [PATCH v4 04/11] watchdog: add support for sl28cpld watchdog

From: Andy Shevchenko
Date: Fri Jun 05 2020 - 10:09:17 EST


On Fri, Jun 05, 2020 at 06:52:00AM -0700, Guenter Roeck wrote:
> On 6/5/20 3:50 AM, Andy Shevchenko wrote:
> > On Fri, Jun 5, 2020 at 1:24 PM Michael Walle <michael@xxxxxxxx> wrote:
> >> Am 2020-06-05 10:14, schrieb Andy Shevchenko:
> >>> On Fri, Jun 5, 2020 at 12:14 AM Michael Walle <michael@xxxxxxxx> wrote:

...

> >>>> +static bool nowayout = WATCHDOG_NOWAYOUT;
> >>>> +module_param(nowayout, bool, 0);
> >>>> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started
> >>>> (default="
> >>>> + __MODULE_STRING(WATCHDOG_NOWAYOUT)
> >>>> ")");
> >>>> +
> >>>> +static int timeout;
> >>>> +module_param(timeout, int, 0);
> >>>> +MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds");
> >>>
> >>> Guenter ACKed this, but I'm wondering why we still need module
> >>> parameters...
> >>
> >> How would a user change the nowayout or the timeout? For the latter
> >> there is
> >> a device tree entry, but thats not easy changable by the user.
> >
> > Yes, it's more question to VIm and Guenter than to you.
> >
>
> Has support for providing module parameters with the kernel command line
> been discontinued/deprecated, or did it run out of favor ? Sorry if I
> missed that.

Latter according to Greg KH. One of the (plenty) examples [1].

[1]: https://www.mail-archive.com/driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx/msg96495.html

> nowayout has a configuration default. A module parameter is sometimes
> provided by drivers to be able to override it. The timeout provided
> via devicetree or on the command line is only the initial/default
> timeout, and the watchdog daemon can change it after opening the
> watchdog device as it sees fit.

Thanks for explanation.

--
With Best Regards,
Andy Shevchenko