diff --git a/.github/workflows/linux_edk2.yml b/.github/workflows/linux_edk2.yml
index 4d4e5e12..04e18e36 100644
--- a/.github/workflows/linux_edk2.yml
+++ b/.github/workflows/linux_edk2.yml
@@ -17,7 +17,8 @@ env:
   # The following should usually be set to 'master' but, in case
   # of a regression, a specific SHA-1 can be specified.
   START_ELF_VERSION: master
-  DTB_VERSION: master
+  # Set to pre HDMI/Audio changes per https://github.com/pftf/RPi4/issues/252
+  DTB_VERSION: b49983637106e5fb33e2ae60d8c15a53187541e4
   DTBO_VERSION: master
 
 jobs:
diff --git a/edk2 b/edk2
index ddaf3926..963671d3 160000
--- a/edk2
+++ b/edk2
@@ -1 +1 @@
-Subproject commit ddaf39263a1ed84e60238622dfed83ff14ecc50a
+Subproject commit 963671d3801a6992d1aa06f05d86e32efa6b205e
diff --git a/edk2-non-osi b/edk2-non-osi
index 1768928b..0544808c 160000
--- a/edk2-non-osi
+++ b/edk2-non-osi
@@ -1 +1 @@
-Subproject commit 1768928be7451a4a8ba43a9acd16ab30582b9511
+Subproject commit 0544808c623bb73252310b1e5ef887caaf08c34b
diff --git a/edk2-platforms b/edk2-platforms
index 085c2fb0..45f96832 160000
--- a/edk2-platforms
+++ b/edk2-platforms
@@ -1 +1 @@
-Subproject commit 085c2fb0221ffb72f5724e21f41e26dd3740947e
+Subproject commit 45f9683253f3a9eca341ff5a8b4c8d8e4ca59430