On Thursday, May 08, 2014 08:56:24 AM Dan Williams wrote:
> On Thu, May 8, 2014 at 4:09 AM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
> > On Wednesday, May 07, 2014 10:37:24 PM Dan Williams wrote:
> >> Unconditionally wake up the child device when the power session is
> >> recovered.
> >
> > [cut]
> >
> >> + /*
> >> + * Revalidate the device if it was requested by
> >> + * usb_port_runtime_resume.
> >> + */
> >> + if (test_and_clear_bit(i, hub->wakeup_bits) && udev) {
> >> + pm_runtime_get_noresume(&udev->dev);
> >> + pm_runtime_barrier(&udev->dev);
> >> + pm_runtime_put_autosuspend(&udev->dev);
> >
> > It looks like you could just call pm_runtime_idle(&udev->dev) after the barrier
> > without the _get and _put around it. Wouldn't that work?
> >
>
> Sure, but the surprise was that an auto suspend enabled device stops
> auto suspending after a barrier.
I see.
Well, _barrier() works pretty much as documented, but its interaction with
autosuspend is weird due to the way the latter is implemented.
I guess we could add a second argument to _barrier() telling it to do
pm_runtime_put() instead of pm_runtime_put_noidle().
Thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
