[PATCH] ARM: dts: bcm283x: Fix vc4's firmware bus DMA limitations

[Nicolas Saenz Julienne]

The bus is virtual and devices have to inherit their DMA constraints
from the underlying interconnect. So add an empty dma-ranges property to
the bus node, implying the firmware bus' DMA constraints are identical to
its parent's.

Fixes: 7dbe8c62ceeb ("ARM: dts: Add minimal Raspberry Pi 4 support")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
---
 arch/arm/boot/dts/bcm2835-rpi.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
index 394c8a71b13b..fd2c766e0f71 100644
--- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
+++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
@@ -15,6 +15,7 @@ soc {
 		firmware: firmware {
 			compatible = "raspberrypi,bcm2835-firmware", "simple-bus";
 			mboxes = <&mailbox>;
+			dma-ranges;
 		};
 
 		power: power {
-- 
2.25.1