diff --git a/target/linux/mvebu/files/arch/arm/boot/dts/armada-370-buffalo-ls421de.dts b/target/linux/mvebu/files/arch/arm/boot/dts/armada-370-buffalo-ls421de.dts
index e8046657920..2a76649ec4f 100644
--- a/target/linux/mvebu/files/arch/arm/boot/dts/armada-370-buffalo-ls421de.dts
+++ b/target/linux/mvebu/files/arch/arm/boot/dts/armada-370-buffalo-ls421de.dts
@@ -209,6 +209,10 @@
 	};
 };
 
+&coherencyfab {
+	broken-idle;
+};
+
 &eth1 {
 	pinctrl-0 = <&ge1_rgmii_pins>;
 	pinctrl-names = "default";