From 320866b9853a8478e75120cc9ff8796489ad8e54 Mon Sep 17 00:00:00 2001
From: Ivan Petkov <ivanppetkov@gmail.com>
Date: Mon, 16 Jan 2023 19:57:10 -0800
Subject: [PATCH] raspberry-pi/4/dtmerge: fix application of overlays

Previously whenever an overlay was found to be incompatible with a base
device tree blob, the entire base dtb would be skipped in favor of
processing the next one. This had the unfortunate effect where overlays
would not fully be applied if any incompatibility was found. For
example, this is an issue with build device trees specific for one
flavor of raspberry pi if the overlay was not compatible _everywhere_.

The solution is to forego the `continue` keyword if an overlay is in
compatible and instead use a compound conditional statement to skip
incompatible overlays but continue trying to apply it to any remaining
dtbs.
---
 raspberry-pi/4/apply-overlays-dtmerge.nix | 30 +++++++++++------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/raspberry-pi/4/apply-overlays-dtmerge.nix b/raspberry-pi/4/apply-overlays-dtmerge.nix
index 8499503..e5b52d3 100644
--- a/raspberry-pi/4/apply-overlays-dtmerge.nix
+++ b/raspberry-pi/4/apply-overlays-dtmerge.nix
@@ -24,26 +24,24 @@ with lib; (base: overlays': stdenvNoCC.mkDerivation {
       # skip incompatible and non-matching overlays
       if [[ ! "$dtbCompat" =~ "$overlayCompat" ]]; then
         echo "Skipping overlay ${o.name}: incompatible with $(basename "$dtb")"
-        continue
-      fi
-      ${optionalString ((o.filter or null) != null) ''
-      if [[ "''${dtb//${o.filter}/}" ==  "$dtb" ]]; then
-        echo "Skipping overlay ${o.name}: filter does not match $(basename "$dtb")"
-        continue
-      fi
+      elif ${if ((o.filter or null) == null) then "false" else ''
+        [[ "''${dtb//${o.filter}/}" ==  "$dtb" ]]
       ''}
+      then
+        echo "Skipping overlay ${o.name}: filter does not match $(basename "$dtb")"
+      else
+        echo -n "Applying overlay ${o.name} to $(basename "$dtb")... "
+        mv "$dtb"{,.in}
 
-      echo -n "Applying overlay ${o.name} to $(basename "$dtb")... "
-      mv "$dtb"{,.in}
+        # dtmerge requires a .dtbo ext for dtbo files, otherwise it adds it to the given file implicitly
+        dtboWithExt="$TMPDIR/$(basename "${o.dtboFile}").dtbo"
+        cp -r ${o.dtboFile} "$dtboWithExt"
 
-      # dtmerge requires a .dtbo ext for dtbo files, otherwise it adds it to the given file implicitly
-      dtboWithExt="$TMPDIR/$(basename "${o.dtboFile}").dtbo"
-      cp -r ${o.dtboFile} "$dtboWithExt"
+        dtmerge "$dtb.in" "$dtb" "$dtboWithExt"
 
-      dtmerge "$dtb.in" "$dtb" "$dtboWithExt"
-
-      echo "ok"
-      rm "$dtb.in" "$dtboWithExt"
+        echo "ok"
+        rm "$dtb.in" "$dtboWithExt"
+      fi
       '')}
 
     done'';