Re: [PATCH] sh_eth: pm_runtime should not need null operations

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Ben,

On Fri, Mar 21, 2014 at 11:15 AM, Ben Dooks <ben.dooks@codethink.co.uk> wrote:
> The driver has a no-op for the pm_runtime callbacks but
> the pm_runtime core should correctly ignore drivers without
> any pm_rumtime callback ops.

The pm_runtime core doesn't ignore non-existing runtime_{suspend,resume}
callbacks, it turns them into a failure withv -ENOSYS.
Only non-existing runtime_idle callbacks are ignored.

rpm_suspend():

        callback = rpm_get_suspend_cb(dev);

        retval = rpm_callback(callback, dev);
        if (retval)
                goto fail;

(rpm_callback() returns -ENOSYS if !callback).

pm_runtime_force_suspend():

        callback = rpm_get_suspend_cb(dev);

        if (!callback) {
                ret = -ENOSYS;
                goto err;
        }

Same for resume.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds