Re: Docking support?

[Holger Macht <hmacht@suse.de>]

On Fri 08. Jun - 09:04:03, Kristen Carlson Accardi wrote:
> On Fri, 7 Nov 2036 16:00:45 +0100
> Holger Macht <hmacht@suse.de> wrote:
> 
> > On Fri 08. Jun - 18:47:06, Samuel Thibault wrote:
> > [...]
> > > Also, I'd really like to receive ACPI docking events in userland for
> > > triggering video devices configuration for instance.
> > 
> > Via udev. Unfortunately....
> > 
> > I just tries and it doesn't work properly.
> > 
> > Dock driver contains something like this:
> > 
> > ---
> >        /*
> >         * here we need to generate the undock
> >         * event prior to actually doing the undock
> >         * so that the device struct still exists.
> >         */
> >         dock_event(ds, event, UNDOCK_EVENT);
> >         hotplug_dock_devices(ds, ACPI_NOTIFY_EJECT_REQUEST);
> >         undock(ds);
> >         eject_dock(ds);
> > ---
> > 
> > When udev receives the KOBJ_CHANGE event triggered by dock_event(), some
> > application or udev itself does read the content of
> > /sys/devices/platform/dock.0/docked. But the value is not updated
> > yet. Checking manually with cat, it sometimes even needs up to two seconds
> > for the right value (0) to show up. So we cannot rely on getting the real
> > state at the point in time where the udev event is received.
> > 
> > At first, function dock_event(..) doesn't need any of the passed
> > arguments. It only makes use of the static platform_device dock_device
> > object to execute a kobject_uevent(). So wouldn't it be save to execute
> > the dock_event() _after_ actually undocking? Something like the following?
> 
> Actually it does - the latest patches sent to Len contain modifications
> to pass an ENV value with the dock event so that userspace can use that
> to determine whether we are doing or undocking.   You might check out
> the "immediate_undock" module parameter patch that I also sent to Len that
> will allow you to write scripts to do work before the undock actually
> happens - http://marc.info/?l=linux-kernel&m=117874881923973&w=2

Oh yes, I saw the immediate_undock patch, but the one with the uevent
changes somehow slipped through my attention. Thanks.

 - Holger