From ed83bac1d98aa3818331685d968444dbda66dc28 Mon Sep 17 00:00:00 2001
From: Atemu <atemu.main@gmail.com>
Date: Sat, 22 Feb 2020 12:45:47 +0100
Subject: [PATCH] undervolt: make timer opt-in

It should no longer be needed but is worth keeping around in case it is
---
 nixos/modules/services/hardware/undervolt.nix | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/services/hardware/undervolt.nix b/nixos/modules/services/hardware/undervolt.nix
index 1f1a6d674787..054ffa35050a 100644
--- a/nixos/modules/services/hardware/undervolt.nix
+++ b/nixos/modules/services/hardware/undervolt.nix
@@ -103,6 +103,17 @@ in
         The temperature target on battery power in Celsius degrees.
       '';
     };
+
+    useTimer = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to set a timer that applies the undervolt settings every 30s.
+        This will cause spam in the journal but might be required for some
+        hardware under specific conditions.
+        Enable this if your undervolt settings don't hold.
+      '';
+    };
   };
 
   config = mkIf cfg.enable {
@@ -126,7 +137,7 @@ in
       };
     };
 
-    systemd.timers.undervolt = {
+    systemd.timers.undervolt = mkIf cfg.useTimer {
       description = "Undervolt timer to ensure voltage settings are always applied";
       partOf = [ "undervolt.service" ];
       wantedBy = [ "multi-user.target" ];