From c84d81541ec6356305bc2175d90ee647bb1a5920 Mon Sep 17 00:00:00 2001
From: Arseniy Seroka <ars.seroka@gmail.com>
Date: Fri, 23 May 2014 14:53:24 +0400
Subject: [PATCH] alsa: add option to change system wide configuration

---
 nixos/modules/services/audio/alsa.nix | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/nixos/modules/services/audio/alsa.nix b/nixos/modules/services/audio/alsa.nix
index 9a70d9edfa7..7699b3bff3e 100644
--- a/nixos/modules/services/audio/alsa.nix
+++ b/nixos/modules/services/audio/alsa.nix
@@ -9,6 +9,8 @@ let
 
   soundState = "/var/lib/alsa/asound.state";
 
+  configPaht = "asound.conf";
+
 in
 
 {
@@ -35,6 +37,17 @@ in
         '';
       };
 
+      extraConfig = mkOption {
+        type = types.lines;
+        default = '''';
+        example = ''
+          defaults.pcm.!card 3
+        '';
+        description = ''
+          Set addition configuration for system-wide alsa.
+        '';
+      };
+
     };
 
   };
@@ -46,6 +59,11 @@ in
 
     environment.systemPackages = [ alsaUtils ];
 
+    environment.etc = [ { source = config.sound.extraConfig;
+                          target = configPath;
+                        }
+                      ];
+
     # ALSA provides a udev rule for restoring volume settings.
     services.udev.packages = [ alsaUtils ];