Bug#347680: Xorg breaks acpid

[Michel Dänzer]

On Mon, 2006-01-23 at 13:15 +0100, Lex Spoon wrote:
> Marcus's analysis looks right to me:
> > > But who can tell which is the grand-piece-of-sw that has the exclusive
> > > right to open /proc/acpi/event?
> > The one which has been designed to multiplex the events to make them
> > available to other programs, and it's acpid.
> 
> The standard Debian setup is to use acpid to multiplex the event stream.
>  Even if it is possible to run with acpid, that should be a different,
> non-standard option.
> 
> There are lots of reasons to multiplex in userspace instead of in the
> kernel.  Among these is that a userspace multiplexer can filter and
> modify the stream as it goes by, and a userspace multiplexer can pull
> events from multiple sources including virtual events injected by other
> sources than the raw hardware.  The earlier comments that obviously the
> kernel should multiplex just aren't right.  Doing it in userspace makes
> sense, and if it is done in userspace, then additionally doing it in the
> kernel would be a bad thing.
> 
> At any rate, the current strategy isn't right.  If the system is using
> acpid--the most common configuration--then it is a bug for X to get in
> the way of acpid.  
> 
> It is laudable that Xorg currently tries to support ACPI even when acpid
> is not running.  However, this is an unusual and only marginally useful
> configuration, isn't it?  Thus, if nothing else, it would seem to make
> sense to simply remove the non-acpid ACPI support when compiling for
> Debian.  In that case, the party line would be, if you want to use ACPI,
> then you install acpid and programs talk to that.
> 
> If it is still desirable to make X work without acpid around, then that
> should surely be a non-standard configuration which requires an
> *explicit* configuration option on the X server.  This does not appear
> worthwhile for Debian, since we do have acpid easily installable, but
> maybe it is sufficiently worthwhile for other Linux distributions that
> it is worth including.

I tend to agree, but I think that this discussion belongs upstream, so
I'm CC'ing the xorg list.

Background for the xorg list: Debian is currently using a patch which
makes the X server open /proc/acpi/event if acpid goes away, to avoid
excessive attempts to access the acpid socket. The problem is that this
prevents acpid from restarting.


-- 
Earthling Michel Dänzer      |     Debian (powerpc), X and DRI developer
Libre software enthusiast    |   http://svcs.affero.net/rm.php?r=daenzer