Re: [PATCH 3/3] PCI / ACPI: Handle sibling devices sharing power resources

Rafael J. Wysocki
2019-06-06T14:27:34Z

On Thu, Jun 6, 2019 at 4:17 PM Mika Westerberg
<mika.westerberg@linux.intel.com> wrote:
>
> On Thu, Jun 06, 2019 at 04:08:11PM +0200, Rafael J. Wysocki wrote:
> > That isn't necessary IMO as long as the device are not accessed. If
> > the kernel thinks that a given device is in D3cold and doesn't access
> > it, then it really doesn't matter too much what state the device is in
> > physically. On the first access the device should be reinitialized
> > anyway.
>
> But if the device is configured to wake. For example when it detects a
> hotplug that state is gone when it goes to D0unitialized.

For this we'll need a pm_runtime_resume() of the dependent device on
the resource going "on".

That means we need a list of devices to resume when the resource goes
"on" after being taken "off".