From 64afb7c12df56edf5070ddd1e92a21bf5d059fdf Mon Sep 17 00:00:00 2001
From: Tom Bereknyei <tomberek@gmail.com>
Date: Sun, 21 Jul 2019 21:49:13 -0400
Subject: [PATCH] Wifi fixed by removing iwlwifi-cc-a0-48.ucode

---
 dell/xps/15-7590/README.wiki |  5 ++++-
 dell/xps/15-7590/default.nix | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/dell/xps/15-7590/README.wiki b/dell/xps/15-7590/README.wiki
index b323b3171883..b583b19d55d5 100644
--- a/dell/xps/15-7590/README.wiki
+++ b/dell/xps/15-7590/README.wiki
@@ -22,7 +22,10 @@ These settings are needed both for booting the final install, and installer itse
 * ''Disable Intel hardware RAID and use AHCI instead.'' Intel doesn't seem to provide a working linux driver for this.  (If you just have SSD it's pointless and just slows things down needlessly anyways.)
 
 === Wifi ===
-Wifi does not work with kernels older than 5.1 (firmware not present) or newer (https://bbs.archlinux.org/viewtopic.php?id=247705)
+~~Wifi does not work with kernels older than 5.1 (firmware not present) or newer~~ (https://bbs.archlinux.org/viewtopic.php?id=247705)
+
+Update: The 48.ucode causes the Killer wifi card to crash. The iwlfwifi-cc-a0-46.ucode works perfectly. default.nix contains an overlay that removes the offending ucode from the linux-firmware bundle.
+
 ```
   # Use the systemd-boot EFI boot loader.
   boot.loader.systemd-boot.enable = true;
diff --git a/dell/xps/15-7590/default.nix b/dell/xps/15-7590/default.nix
index a3540e7cf324..4a9030ab30c9 100644
--- a/dell/xps/15-7590/default.nix
+++ b/dell/xps/15-7590/default.nix
@@ -11,4 +11,24 @@
   boot.kernelPackages = pkgs.linuxPackages_5_1;
   boot.loader.efi.canTouchEfiVariables = lib.mkDefault true;
 
+  # The 48.ucode causes the Killer wifi card to crash.
+  # The iwlfwifi-cc-a0-46.ucode works perfectly
+  nixpkgs.pkgs = import <nixpkgs> {
+    config.allowUnfree = true;
+    overlays = [
+      (self: super: {
+        firmwareLinuxNonfree = super.firmwareLinuxNonfree.overrideAttrs (old: {
+          src = super.fetchgit{
+            url = "https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git";
+            rev = "bf13a71b18af229b4c900b321ef1f8443028ded8";
+            sha256 = "1dcaqdqyffxiadx420pg20157wqidz0c0ca5mrgyfxgrbh6a4mdj";
+          };
+          postInstall = ''
+            rm $out/lib/firmware/iwlwifi-cc-a0-48.ucode
+          '';
+          outputHash = "0dq48i1cr8f0qx3nyq50l9w9915vhgpwmwiw3b4yhisbc3afyay4";
+        });
+      })
+    ];
+  };
 }