From 198fdd98fb1c226f7021a02146498f767520f315 Mon Sep 17 00:00:00 2001
From: Peter Hoeg <peter@hoeg.com>
Date: Fri, 1 Nov 2019 12:46:59 +0800
Subject: [PATCH 1/2] linuxPackages.evdi: 1.6.2 -> 1.6.3

This works with kernel 5.3.x
---
 pkgs/os-specific/linux/evdi/default.nix | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/pkgs/os-specific/linux/evdi/default.nix b/pkgs/os-specific/linux/evdi/default.nix
index 2508fb851a8..72f3b1fbd9c 100644
--- a/pkgs/os-specific/linux/evdi/default.nix
+++ b/pkgs/os-specific/linux/evdi/default.nix
@@ -2,20 +2,23 @@
 
 stdenv.mkDerivation rec {
   pname = "evdi";
-  version = "1.6.2";
+  version = "1.6.3";
 
   src = fetchFromGitHub {
     owner = "DisplayLink";
     repo = pname;
     rev = "v${version}";
-    sha256 = "0ajjsh1fw7w0k28r6qq7kh3qcr87gzzjp8s890algbglynlafzfw";
+    sha256 = "1gp8xbhd5pmcl95izhpvw9gxfcsbv5f80s6q39l4y3z9j734rb8j";
   };
 
   nativeBuildInputs = kernel.moduleBuildDependencies;
 
   buildInputs = [ kernel libdrm ];
 
-  makeFlags = [ "KVER=${kernel.modDirVersion}" "KDIR=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build" ];
+  makeFlags = [
+    "KDIR=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build"
+    "KVER=${kernel.modDirVersion}"
+  ];
 
   hardeningDisable = [ "format" "pic" "fortify" ];
 
@@ -26,9 +29,9 @@ stdenv.mkDerivation rec {
 
   meta = with stdenv.lib; {
     description = "Extensible Virtual Display Interface";
-    platforms = platforms.linux;
+    homepage = "https://www.displaylink.com/";
     license = with licenses; [ lgpl21 gpl2 ];
-    homepage = https://www.displaylink.com/;
-    broken = versionOlder kernel.version "4.9" || versionAtLeast kernel.version "5.3" || stdenv.isAarch64;
+    platforms = platforms.linux;
+    broken = versionOlder kernel.version "4.9" || stdenv.isAarch64;
   };
 }

From d936b17d144ee2a479e5288e6f90bc8725fc33d1 Mon Sep 17 00:00:00 2001
From: Peter Hoeg <peter@hoeg.com>
Date: Fri, 1 Nov 2019 12:48:13 +0800
Subject: [PATCH 2/2] nixos/displaylink: write out required xorg.conf fragment

Invoke xrandr to actually connect the device.

Additionally, we let systemd create the logs directory and use our module loader
instead of handling it manually.
---
 nixos/modules/hardware/video/displaylink.nix | 22 ++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/nixos/modules/hardware/video/displaylink.nix b/nixos/modules/hardware/video/displaylink.nix
index 669ac849cba..912f53da836 100644
--- a/nixos/modules/hardware/video/displaylink.nix
+++ b/nixos/modules/hardware/video/displaylink.nix
@@ -19,6 +19,21 @@ in
   config = mkIf enabled {
 
     boot.extraModulePackages = [ evdi ];
+    boot.kernelModules = [ "evdi" ];
+
+    environment.etc."X11/xorg.conf.d/40-displaylink.conf".text = ''
+      Section "OutputClass"
+        Identifier  "DisplayLink"
+        MatchDriver "evdi"
+        Driver      "modesetting"
+        Option      "AccelMethod" "none"
+      EndSection
+    '';
+
+    # make the device available
+    services.xserver.displayManager.sessionCommands = ''
+      ${lib.getBin pkgs.xorg.xrandr}/bin/xrandr --setprovideroutputsource 1 0
+    '';
 
     # Those are taken from displaylink-installer.sh and from Arch Linux AUR package.
 
@@ -47,18 +62,13 @@ in
       description = "DisplayLink Manager Service";
       after = [ "display-manager.service" ];
       conflicts = [ "getty@tty7.service" ];
-      path = [ pkgs.kmod ];
 
       serviceConfig = {
         ExecStart = "${displaylink}/bin/DisplayLinkManager";
         Restart = "always";
         RestartSec = 5;
+        LogsDirectory = "displaylink";
       };
-
-      preStart = ''
-        mkdir -p /var/log/displaylink
-        modprobe evdi
-      '';
     };
 
   };