2.6.23 and newer kernel and option ACPI_PROC_EVENT.

[David Woodhouse]

On Sat, 2007-09-01 at 11:04 -0400, David Zeuthen wrote:
> (Moving from fedora-devel-list to fedora-kernel-list)
> 
> On Wed, 2007-08-29 at 17:14 -0400, Dave Jones wrote:
> > On Wed, Aug 29, 2007 at 11:38:04AM +0200, Zdenek Prikryl wrote:
> >  > 
> >  > > I think acpid will have to be ported to this new ABI.
> >  > >   
> >  > Yes, acpid will have to be ported, but it takes some time. But 
> >  > meanwhile,  I think it is useful to enable old code.
> > 
> > Yes, I'll turn it back on for F8. I disabled it to find out
> > just how much stuff is depending on it.  Seems just acpid :-)
> 
> Also hal. We still need /proc/acpi/event as the ACPI battery and
> ac_adapter drivers in the kernel haven't been ported to use sysfs.
> Hence, without the /proc/acpi/event socket we don't get change
> notifications [1]. 
> 
> Actually I'm unsure what the sysfs interfaces will end up looking like
> and how change notification will work. Does anyone know? I know dwmw2
> did some work here (for OLPC) defining a sysfs class but I've also seen
> other patches with different interfaces fly by. Richard added support in
> hal for at least one of these [2] so maybe it will just work out of the
> box. dwmw2?

Sorry for delayed response -- I am currently unable to read the mailbox
you sent this to.

The sysfs battery class stuff (which also covers AC since they're really
quite similar) is merged into 2.6.23. You get a uevent when stuff
changes, although the precise details of _when_ you get that uevent are
dependent on the back end, and you might find that some back ends don't
do it yet at all. We could do with standardising that somehow, or at
least having some way to let userspace _know_ that it needs polling.

The ACPI back end isn't yet merged -- it's being developed by Alexey
Starikovskiy, and can be found on the linux-acpi mailing list:
http://www.mail-archive.com/linux-acpi@vger.kernel.org/msg08858.html
http://www.mail-archive.com/linux-acpi@vger.kernel.org/msg08856.html
http://www.mail-archive.com/linux-acpi@vger.kernel.org/msg08859.html
http://www.mail-archive.com/linux-acpi@vger.kernel.org/msg08857.html
http://www.mail-archive.com/linux-acpi@vger.kernel.org/msg08855.html

-- 
dwmw2