Re: [linux-pm] [PATCH 0/6] [-mm]: ACPI: duplicate ACPI procfs functions in sysfs

Len Brown
2007-01-25T03:33:59Z

On Sunday 07 January 2007 00:54, Matthew Garrett wrote:
> On Sat, Jan 06, 2007 at 02:21:41PM -0800, David Brownell wrote:
>
> > Please tell me you mean "devices with a /sys/devices/.../power/wakeup"
> > attribute. And that ACPI is finally going to start working with those
> > attributes ...

I agree that must be the goal.

> It's not necessarily possible to map from an ACPI object with a wakeup
> capability to a Linux device, so there's going to have to be some degree
> of interface nastiness. However, some devices can be sensibly mapped,
> and ideally those should be integrated into
> /sys/devices/.../power/wakeup.

True. Some ACPI "devices" don't exist except for in ACPI mode.
Rui exposed them in some earlier patches in the sysfs patch series
which are now in -mm via git-acpi.patch.

> However, I'm not entirely sure /how/ that integration should happen. If
> both the Linux driver and ACPI know how to enable wakeup for a device,
> what should writing to power/wakeup do?
>
> > > So /proc/acpi/wakeup is deprecated by
> > > /sys/devices/acpi_system/.../xxx/sleep_state && wakeup.
> >
> > Why is ACPI still not coupling such information to the REAL device
> > nodes? On my laptop, right now without any wakeup-capable USB
> > devices attached, the appended script produces:
>
> So for example, the PCI0 device on my Thinkpad is an ACPI wakeup device.
> Investigating the DSDT suggests that this is just a wrapper around a
> bunch of platform devices, including the ISA bridge. In this case, what
> real device should we be associating it with?

yeah, we'll have to figure out what that really means.

thanks,
-Len