Re: Hotplug events for system suspend/resume

From: Nigel Cunningham
Date: Tue May 11 2004 - 23:06:28 EST


On Wed, 12 May 2004 12:44, Todd Poynor wrote:
> The patch hooks into the power subsystem prior to freezing processes and
> after unfreezing processes, so I don't think it's a concern (unless
> something is using the power subsystem rather oddly). This patch sends
> a single notification of system suspend and a single notification of
> system resume, in case there's any confusion with the individual device
> state change notifiers also recently discussed. It's been run
> successfully on one ACPI system and one non-ACPI system.


> > In my mind, this approach is simpler and makes more sense: userspace
> > should worry about userspace actions related to suspending before calling
> > kernelspace. Kernel space should then only worry about saving and
> > restoring driver states and should be transparent to user space. ...
> Agreed, with the minor reservations listed in a previous email (suspend
> initiated by drivers must coordinate ad-hoc with userspace, etc.).

You're thinking ACPI drivers initiating a suspend? They would do it through
acpid, wouldn't they? At least that's the glue I use to get my sleep button
to initiate a suspend. I would assume thermal events would/should work the

> I'll let anybody who cares more deeply about this speak up now,
> otherwise this isn't a battle I'll be fighting on behalf of others any
> more. Thanks -- Todd

:> I wasn't meaning to make it a battle!


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