Re: [PATCH 0/5] ACPI: procfs/sysfs/debugfs code cleanup

[Len Brown <lenb@kernel.org>]

On Fri, 11 Jun 2010, Zhang Rui wrote:

> This patch set mainly cleans up the ACPI procfs/sysfs/debugfs code.
> 
> 1. removes the deprecated ACPI procfs I/F, including
>    /proc/acpi/debug_layer
>    /proc/acpi/debug_level
>    /proc/acpi/info
>    /proc/acpi/dsdt
>    /proc/acpi/fadt
>    because the sysfs I/F have been working for years without any problems.

Documentation/feature-removal-schedule.txt has warned
that we'd delete all of /proc/acpi/ for a long time now,
but we seem to have somewhat stalled out on that quest.

After this patch series, it seems like a good time to take inventory
of /proc/acpi/, list every file, and list if and when it will go away..
A section in feature-removal-schedule.txt is probably as good a place
as any for this.

Files that are deprecated should all be put under CONFIG_ACPI_PROCFS
where they should wait to be deleted for at least one release.

(Also, this patch series needs to update drivers/acpi/Kconfig comments
 because it removes some files that were aging under CONFIG_ACPI_PROCFS)

/proc/acpi/event was deemed too special to age under
CONFIG_ACPI_PROCFS, and so it has its own CONFIG_ACPI_PROC_EVENT
I think losing its default =y now would make sense,
and move it under CONFIG_ACPI_PROCFS in a year?
and hopefully delete it entirely in another year?

CONFIG_PROCFS_POWER should proably now also lose its default =y.
If current user-space no longer needs this, then
in a few releases it can get sucked under CONFIG_ACPI_PROCFS.

About 50% of button.c is suport for /proc/acpi/button/* --
it will be satisfying to simplify that one.
We tried to delete that code once, but somebody reads
the lid status, and so we restored it.
I don't know if we can get the LID status from anyplace else,
so that file may have to remain longer, but the other
/proc/acpi/button files are useuless and can go in 1 release.

thanks,
Len Brown, Intel Open Source Technology Center