Is this both required for suspend and hibernate?

Commands executed when the machine powers down. That is, they're executed both when the system shuts down and when it goes to suspend or hibernation.

for me it's required. wpa_supplicant stops on suspend too.

I mean does brcmfmac also breaks suspend or just hibernate?

ah, yeah, it does not break resume after suspend, so only required for hibernate.

Ok. So it should be only unloaded for hypernate-sleep.target and hybrid-sleep.target? https://github.com/NixOS/nixpkgs/blob/950bb1452032e8e839ddb2af0dc85350c73025a6/nixos/modules/config/power-management.nix#L92

That would require two services, but systemd's script field should keep the boiler code needed for this low.

You can just create new systemd services:

    systemd.services.post-resume-brcmfmac = { 
        description = "Post-Resume Actions";
        after = [ "hibernate.target" "hybrid-sleep.target" ];
        script = ''
          # here goes your code
        '';
        serviceConfig.Type = "oneshot";
      };

and the same for pre-hibernate.

added.

recalled another case: sometimes on lid close (sleep/suspend) brcmfmac could crash itself, so i guess the better approach would be to still use it in powerUp/Down commands of PM. unload/load driver.

if that's too hacky, let's leave it as it, and I might keep it in my local configuration for now.

Ok. If this is the case, than we keep the original.

added lib.mkBefore for both Up/Down commands.

@infinisil How can we make this string appended after our own module value? We are currently doing rmmod. I think there was a way to do priorities.

Not sure how rmmod relates, but if you mean how to order different powerUpCommand assignments, you can use mkBefore or mkAfter for that, which make sure the value is ordered before or after the default priority.

Thanks! This were the helper functions I was looking for.

@sevenfourk If you revert to the previous powerManagement.powerUpCommands/powerDownCommands
but use mkBefore:

powerManagement.powerUpCommands = lib.mkBefore ''
  ${pkgs.kmod}/bin/modprobe brcmfmac
'';

Than users can just follow the readme to restart their network manager daemon of choice and the ordering will make sure that their services gets added after the modprobe.

thanks guys, leaving ordering for README example as is. added lib.mkBefore for module manipulation.