Is it possible to remove a local pkg configuration and substitude by pkg original configuration?
If by configuration you mean a package-provided file, then yes.
Easy option - rename the original (or delete it as you prefer) and reinstall the package.
Not as easy option - rename the original (or delete it as you prefer), extract manually the config file from /var/cache/pacman/pkg/foo.tar.xz.
Welcome to Arch.
When I remove a pkg which have altered config file, and re-install later, it don't use last install config file (or ask which one to use).
Why the initial question : I probably made few wrong configs to restore suspend and powerkey management (broken after pacman -Syu).
I belive scraps of hand made config may impede right running of power management, and whant to zero all related pkg.
Will ask in admin discussion topic if it's not a pacman stuff.
Your best option is to hunt down the "scraps" and tidy them up.
When you remove a package pacman will sometimes save the configuration with a .pacsave extension. If you wish to prevent this from happening you need to use the "-n" option.
All men have stood for freedom...
For freedom is the man that will turn the world upside down.
Sorry to answer so late, I made many tests using suggestions.
I don't remember which files I changed. I made a ad-hoc config ~1.5 years ago, and probably some wrong changes one month ago after an update. I belive it was easy to solve and didn't anotate nothing.
I use "power management" wiki page, so I probably install and try to make work:
Laptop Mode Tools
and specifc laptop scripts (I have a Asus eepc).
maybe I made change in kernel and/or udev rules.
Using ".pacsave" as suggested, I identified and old config file of acpi-eeepc-generic
I install it again, and activate the pacsave config file. No effect.
For all tentatives I try with and without windows manager (xserver/openbox. lxde is installed but not used) using "systemctl suspend"
The problem seams to appear when systemd subtitute grub. "power management" wiki page alert about possible conflict systemd/acpi.
I removed acpi-eeepc-generic, acpi, acpid, pm-utils, pm-quirks.
Nothing new :
"systemctl suspend" suspend but don't wake up.
power buton don't shutdown
Some suggestion ?! ;-)