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

[Len Brown <lenb@kernel.org>]

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