1 files changed, 42 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.10/950-0730-overlays-Reduce-Pi-4-vc4-CMA-size-to-320MB.patch b/target/linux/bcm27xx/patches-5.10/950-0730-overlays-Reduce-Pi-4-vc4-CMA-size-to-320MB.patch
new file mode 100644
index 0000000000..393c9c3273
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.10/950-0730-overlays-Reduce-Pi-4-vc4-CMA-size-to-320MB.patch
@@ -0,0 +1,42 @@
+From 0d5d8f373125e5bdf331d8fc579b2cf18171c1c0 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.com>
+Date: Tue, 3 Aug 2021 11:32:30 +0100
+Subject: [PATCH] overlays: Reduce Pi 4 vc4 CMA size to 320MB
+
+Reduce the default CMA allocation requested by the vc4-kms-v3d-pi4 and
+vc4-fkms-v3d-pi4 overlays to 320MB.
+
+Use magic values of the form (<n>*64 - 4)MB to encode default values
+of <n>*64MB, allowing these defaults to be distinguished from values
+set explicitly by the user with the usual overlay parameters (e.g.
+"cma-384"). Only default values will be capped if the Pi RAM is too
+small or the gpu_mem setting too large for it to be viable.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.com>
+---
+ arch/arm/boot/dts/overlays/vc4-fkms-v3d-pi4-overlay.dts | 2 +-
+ arch/arm/boot/dts/overlays/vc4-kms-v3d-pi4-overlay.dts  | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+--- a/arch/arm/boot/dts/overlays/vc4-fkms-v3d-pi4-overlay.dts
++++ b/arch/arm/boot/dts/overlays/vc4-fkms-v3d-pi4-overlay.dts
+@@ -8,7 +8,7 @@
+ #include "cma-overlay.dts"
+ 
+ &frag0 {
+-       size = <(512*1024*1024)>;
++	size = <((320-4)*1024*1024)>;
+ };
+ 
+ / {
+--- a/arch/arm/boot/dts/overlays/vc4-kms-v3d-pi4-overlay.dts
++++ b/arch/arm/boot/dts/overlays/vc4-kms-v3d-pi4-overlay.dts
+@@ -10,7 +10,7 @@
+ #include "cma-overlay.dts"
+ 
+ &frag0 {
+-       size = <(512*1024*1024)>;
++	size = <((320-4)*1024*1024)>;
+ };
+ 
+ / {