How to configure ec_sys with write_support=1

ISW need ec_sys module with option write_support=1. To set that, we first need to check if ec_sys is a builtin kernel module or not:

grep ec_sys /lib/modules/$(uname -r)/modules.builtin

If it show kernel/drivers/acpi/ec_sys.ko the module is builtin.

Once you have the info, two scenarios:

• ec_sys IS a builtin kernel module:
  • Add ec_sys.write_support=1 in /etc/default/grub.*¹
  • Update grub: update-grub(Manjaro) or grub-mkconfig -o /boot/grub/grub.cfg(Arch)
  • Reboot.
• ec_sys IS NOT a builtin kernel module:
  • Copy both isw-ec_sys.conf files provided with same path (AUR package will do it for you):
    • etc/modprobe.d/isw-ec_sys.conf
    • etc/modules-load.d/isw-ec_sys.conf
  • Reboot OR modprobe ec_sys write_support=1.

You can check if it's correctly configured with:

< /sys/module/ec_sys/parameters/write_support
Y

ls -l /sys/kernel/debug/ec/ec0/io
-rw------- 1 root root 0  9 janv. 14:36 /sys/kernel/debug/ec/ec0/io

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*¹Example:GRUB_CMDLINE_LINUX_DEFAULT="quiet ec_sys.write_support=1"