Re: Fix wake GPE enabling

[Dominik Brodowski <linux-X3ehHDuj6sIIGcDfoQAp7BvVK+yQ3ZXh@public.gmane.org>]

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On Wed, Apr 07, 2004 at 02:34:43PM -0700, Moore, Robert wrote:
> 
> No, this does not fit the model correctly.
> 
> It is the responsibility of the upper software to selectively enable the
> devices which are to be used for wakeup.  This is one of the functions
> of the AcpiGpeEnable interface.  The ACPI CA core cannot just blindly
> enable all "wake" GPEs.

However, the ACPI subsystem, and I do not care whether it is the CA core or
any other part, currently does not enable any(!) wake GPEs.

-> wake_enable is not touched directly,
-> events/evgpeblk.c does not care, and according to your opinion, should
   not care.
-> acpi_enable_gpe is _only_ called by drivers/acpi/ec.c, which means it is
   _not_ called for buttons, which are very clearly needed in most cases to
   wake up a system.

At least for buttons, the ACPI subsystem should enable their wake
functionality, e.g. the wake GPEs, unconditionally. Having to manually enter
"echo powerbutton > /proc/acpi/wakeup_devices", as the patch in bug #1415
suggests, seems to be overly complicated. However, having this file as
override might be a valid option, I agree.

> The ACPI CA core simply identifies the "wake" GPEs in order to leave
> them disabled during runtime.
> 
> Therefore, in (1) and (2) below, this is the correct behavior.  No
> "wake" GPEs are enabled.

IMHO, (2) is not correct behavior. It is a different thing to
- disable wake GPEs during runtime,
and
- mark wake GPEs as runtime GPEs, which is what the current code does.

Also, as it has been experienced by Linus, for example[*], some "wake" GPEs are also useful to
have during runtime, so the code in acpi_enable_gpe() which disables a GPE
marked as "wake" is flawed. IMO it should be able to set it to both RUNTIME and
WAKE, if it's runtime, enable it during runtime, if it's wake, enable it for
wakeup.

[*] And that's the reason the acpi_disable_wake_gpes_during_runtime flag is
_not_ set to true in Linux 2.6.5, in contrast to the original ACPI patch
sent out. And I'm glad it is this way: with this flag set, my notebook's
keyboard stops functioning...

	Dominik

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