Rebase to flake parts #7

modules/hosts/t2mbp/t2linux/_private/boot-tuning.nix

@@ -0,0 +1,27 @@
+{ ... }: {
+  # T2: align with https://github.com/deqrocks/apple-bce#required-kernel-parameters (suspend stack).
+  # (Older t2linux guidance used s2idle + pcie_ports=compat; deqrocks fork expects deep + auto + pm_async=off.)
+  boot.kernelParams = [
+    "mem_sleep_default=deep"
+    "intel_iommu=on"
+    "iommu=pt"
+    "pcie_ports=auto"
+    "pm_async=off"
+    # https://wiki.t2linux.org/guides/hybrid-graphics/#enabling-the-igpu — helps some post-suspend black screens.
+    "i915.enable_guc=3"
+  ];
+
+  # Hybrid T2 Macs: prefer Intel for display/GL (saves power; avoids broken AMDGPU after resume).
+  # https://wiki.t2linux.org/guides/hybrid-graphics/
+  boot.extraModprobeConfig = ''
+    options apple-gmux force_igd=y
+  '';
+
+  # If the AMD dGPU misbehaves after S3 (Electron apps won’t start, suspend breaks), keep it unloaded.
+  # See https://github.com/deqrocks/apple-bce#notes-for-dgpu-models — drop this list if you need DRI_PRIME
+  # or external displays wired through the dGPU.
+  boot.blacklistedKernelModules = [ "amdgpu" ];
+
+  boot.kernelModules = [ "apple-bce" ];
+  boot.initrd.availableKernelModules = [ "apple-bce" ];
+}