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

Matthew Garrett
2007-01-07T05:54:24Z

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 ...

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.

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?

--
Matthew Garrett | mjg59@srcf.ucam.org