Re: [PATCH v2 6/7] Watchdog: introduce ARM SBSA watchdog driver

[Guenter Roeck <linux@roeck-us.net>]

On Thu, May 21, 2015 at 11:46:53PM +0800, Fu Wei wrote:
> Hi Guenter,
> 
[ ... ]

> >> >> +
> >> >> +       /*
> >> >> +        * Try to determine the frequency from the arch_timer interface
> >> >> +        */
> >> >> +       clk = arch_timer_get_rate();
> >> >
> >> >
> >> > arch_timer_get_rate() does not seem to be exported. Did you try to build
> >> > the driver as module ?
> >>
> >> yes, I have built it as a ko module, that is why I made a patch to
> >> export this interface in the first patch of this patchset
> >>
> >>  but I will confirm it again :-)
> >>
> > Guess I'll give it a try myself. I don't really understand how this
> > can work unless arch_timer_get_rate() is exported in your tree.
> 
> yes, I have exported it , I think it make sense to export it.
> Because other driver maybe need to get system counter info
> 
> Do you agree ? :-)
> 
I don't think it is for me to agree or not. The arm maintainers
will need to be involved. You can not just export such a function
without maintainer Ack.

Having said that, my personal preference would be for the counter
and rate to be exported through the clock subsystem (ie with
clk_get_rate). But that would still not provide the current counter
value, so maybe that isn't even possible.

Thanks,
Guenter