From 0634a2dc9566de977970c78a06c7ea15cd9c890f Mon Sep 17 00:00:00 2001 From: Nicolas Saenz Julienne Date: Wed, 4 Dec 2019 13:56:33 +0100 Subject: ARM: dts: bcm2711: fix soc's node dma-ranges Raspberry Pi's firmware has a feature to select how much memory to reserve for its GPU called 'gpu_mem'. The possible values go from 16MB to 944MB, with a default of 64MB. This memory resides in the topmost part of the lower 1GB memory area and grows bigger expanding towards the begging of memory. It turns out that with low 'gpu_mem' values (16MB and 32MB) the size of the memory available to the system in the lower 1GB area can outgrow the interconnect's dma-range as its size was selected based on the maximum system memory available given the default gpu_mem configuration. This makes that memory slice unavailable for DMA. And may cause nasty kernel warnings if CMA happens to include it. Change soc's dma-ranges to really reflect it's HW limitation, which is being able to only DMA to the lower 1GB area. Fixes: 7dbe8c62ceeb ("ARM: dts: Add minimal Raspberry Pi 4 support") Signed-off-by: Nicolas Saenz Julienne Reviewed-by: Phil Elwell Signed-off-by: Florian Fainelli --- arch/arm/boot/dts/bcm2711.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi index 961bed832755..e2f6ffb00aa9 100644 --- a/arch/arm/boot/dts/bcm2711.dtsi +++ b/arch/arm/boot/dts/bcm2711.dtsi @@ -43,7 +43,7 @@ <0x7c000000 0x0 0xfc000000 0x02000000>, <0x40000000 0x0 0xff800000 0x00800000>; /* Emulate a contiguous 30-bit address range for DMA */ - dma-ranges = <0xc0000000 0x0 0x00000000 0x3c000000>; + dma-ranges = <0xc0000000 0x0 0x00000000 0x40000000>; /* * This node is the provider for the enable-method for -- cgit v1.2.3