linux_pinebookpro_latest: workaround for display init

And follow latest from Nixpkgs

kernel/latest/0001-HACK-Revert-pwm-Read-initial-hardware-state-at-reque.patch

@@ -0,0 +1,51 @@
+From 84517c6e2aac4fb32c8b02b5713297b37c140b4f Mon Sep 17 00:00:00 2001
+From: Samuel Dionne-Riel <samuel@dionne-riel.com>
+Date: Sun, 26 Jul 2020 19:31:59 -0400
+Subject: [PATCH] [HACK] Revert "pwm: Read initial hardware state at request
+ time"
+
+This is a WORKAROUND for the issue where recent kernels will hang at
+display initialization with recent kernels.
+
+This reverts commit cfc4c189bc70b1acc17e6f1abf1dc1c0ae890bd8.
+---
+ drivers/pwm/core.c | 16 ++++++++--------
+ 1 file changed, 8 insertions(+), 8 deletions(-)
+
+diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
+index 004b2ea9b5fd..245e2fcfc779 100644
+--- a/drivers/pwm/core.c
++++ b/drivers/pwm/core.c
+@@ -117,14 +117,6 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
+ 		}
+ 	}
+ 
+-	if (pwm->chip->ops->get_state) {
+-		pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
+-		trace_pwm_get(pwm, &pwm->state);
+-
+-		if (IS_ENABLED(CONFIG_PWM_DEBUG))
+-			pwm->last = pwm->state;
+-	}
+-
+ 	set_bit(PWMF_REQUESTED, &pwm->flags);
+ 	pwm->label = label;
+ 
+@@ -305,6 +297,14 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
+ 		pwm->hwpwm = i;
+ 		pwm->state.polarity = polarity;
+ 
++		if (pwm->chip->ops->get_state) {
++			pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
++			trace_pwm_get(pwm, &pwm->state);
++
++			if (IS_ENABLED(CONFIG_PWM_DEBUG))
++				pwm->last = pwm->state;
++		}
++
+ 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
+ 	}
+ 
+-- 
+2.25.4
+

kernel/latest/default.nix

@@ -1,24 +1,19 @@
-{ stdenv
+{ pkgs, lib, linux_5_7, kernelPatches, ... } @ args:
-, pkgs
-, lib
-, kernelPatches
-, buildPackages
-, fetchFromGitLab
-, perl
-, buildLinux
-, modDirVersionArg ? null
-, ... } @ args:
 
-let
+linux_5_7.override({
-  inherit (stdenv.lib)
+  kernelPatches = lib.lists.unique (kernelPatches ++ [
-    concatStrings
+    pkgs.kernelPatches.bridge_stp_helper
-    intersperse
+    pkgs.kernelPatches.request_key_helper
-    take
+    pkgs.kernelPatches.export_kernel_fpu_functions."5.3"
-    splitString
+    {
-    optionalString
+      name = "pinebookpro-5.7.patch";
-  ;
+      patch = ./pinebookpro-5.7.patch;
-  version = "5.7";
+    }
-  additionalConfig = {
+    {
+      name = "0001-HACK-Revert-pwm-Read-initial-hardware-state-at-reque.patch";
+      patch = ./0001-HACK-Revert-pwm-Read-initial-hardware-state-at-reque.patch;
+    }
+    {
       name = "pinebookpro-config-fixes";
       patch = null;
       extraConfig = ''
@@ -37,35 +32,8 @@ let
         ROCKCHIP_LVDS y
         ROCKCHIP_RGB y
       '';
-  };
+    }
-in
-
-buildLinux (args // {
-  inherit version;
-
-  kernelPatches = lib.lists.unique (kernelPatches ++ [
-    pkgs.kernelPatches.bridge_stp_helper
-    pkgs.kernelPatches.request_key_helper
-    pkgs.kernelPatches.export_kernel_fpu_functions."5.3"
-    additionalConfig
   ]);
-
+})
-  # modDirVersion needs to be x.y.z, will automatically add .0 if needed
+//
-  modDirVersion = if (modDirVersionArg == null) then concatStrings (intersperse "." (take 3 (splitString "." "${version}.0"))) else modDirVersionArg;
+(args.argsOverride or {})
-
-  # branchVersion needs to be x.y
-  extraMeta.branch = concatStrings (intersperse "." (take 2 (splitString "." version)));
-
-  src = fetchFromGitLab {
-    domain = "gitlab.manjaro.org";
-    owner = "tsys";
-    repo = "linux-pinebook-pro";
-    rev = "a8f4db8a726e5e4552e61333dcd9ea1ff35f39f9";
-    sha256 = "1vbach0y28c29hjjx4sc9hda4jxyqfhv4wlip3ky93vf4gxm2fij";
-  };
-
-  postInstall = (optionalString (args ? postInstall) args.postInstall) + ''
-    mkdir -p "$out/nix-support"
-    cp -v "$buildRoot/.config" "$out/nix-support/build.config"
-  '';
-} // (args.argsOverride or {}))