Re: [PATCH 13/13] ACPI: use unique number as bus_id of ACPI device in sysfs

[Len Brown <len.brown@intel.com>]

On Friday 24 November 2006 00:17, Len Brown wrote:
> From: Zhang Rui <rui.zhang@intel.com>
> 
> Previously we used the device name in the DSDT, but would
> crash upon encountering a duplicate.  Also, exposing
> the DSDT device name to the user in a path isn't a
> good idea, becauase it is arbitrary.
> So just add two attributes for each device,
> the full pathname in ACPI namespace and hardware_id.

While this addresses the potential name conflict of the previous version,
I think this needs some work.

$ ls /sys/devices/0
1  10  2  3  4  5  57  6  7  8  9  bus  hid  path  power  subsystem  uevent

Assigning the unique numbers in a depth-first search
leaves irritating gaps -- (see 10 and 57 above).
Instance numbers need to be per-directory.

Also, IMHO, the numbers by  themselves look a little strange,
maybe dev0, dev1, dev%d etc. wouldn't look so strange?

Also, the ACPI spec has some pre-defined root name-spaces, and I think
it makes sense to look up the device name against a small table of
those reserved names and print something more interesting than
a number.

eg. 
_SB	system_bus
_PR processors
_TZ thermal_zones
_SI system_indicators
_GPE events

thanks,
-Len