unify Linux physdev and classdev handling

[Kay Sievers]

On Tue, 2006-10-10 at 13:10 -0400, David Zeuthen wrote:
> On Tue, 2006-10-10 at 10:55 +0200, Kay Sievers wrote:
> > Future Linux kernels will not export any property like "physical",
> > "logical", class, or "bus" device. At the time the current compatibility
> > interfaces will be removed from the kernel (in 2-3 years), HAL will not
> > even be able to determine such properties, even if it wanted to.
> > 
> > The kernels class/bus interface will be around for a while, but HAL
> > should stop handling the devices differently. This patch unifies all
> > device handling into a single code path.
> 
> What Linux kernel version / udev version will this make us depend on? If
> it's not more recent than 2.6.17 / 089 just go for it. Otherwise we
> should probably discuss it a bit more...

It should not introduce any new dependency. It's just that it will work
with our current driver-core patched kernel, that may find its way
upstream in a few months:
  http://www.kernel.org/git/?p=linux/kernel/git/gregkh/patches.git;a=blob;hb=HEAD;f=driver-class/sys-subsys-unification.patch

With this patch, HAL does device parent-relationships only, instead of
stacking class devices on top of bus devices, and handle both device
types with the same code inside of HAL (merge classdev.c and physdev.c
into devices.c).

> > In a future patch, we should also remove/rename all properties which
> > include "*physical*" and get rid of the linux.sysfs_path_devices
> > property.
> 
> Yeah. Feel free to nuke linux.sysfs_path_device already, it's a bug if
> something outside HAL depends on it.

Fine. I'll look into this after finishing the coldplug code to work with
a kernel that doesn't have /sys/class /sys/block and /sys/bus anymore.

Kay