From aa8277959d7746d231f1f3c8050f01696f825ae3 Mon Sep 17 00:00:00 2001
From: Yan Lin <github@yanlincs.com>
Date: Mon, 20 Oct 2025 18:01:21 +0200
Subject: [PATCH] enforce deep sleep mode

---
 hosts/nixos/thinkpad/system.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hosts/nixos/thinkpad/system.nix b/hosts/nixos/thinkpad/system.nix
index 297dc7a..8056c65 100644
--- a/hosts/nixos/thinkpad/system.nix
+++ b/hosts/nixos/thinkpad/system.nix
@@ -40,6 +40,8 @@ in
     "i915.enable_fbc=1"
     # Disable GPU power management debugging
     "drm.debug=0"
+    # Prefer S3 deep sleep over s2idle
+    "mem_sleep_default=deep"
   ];
 
   # Enable firmware updates