| From 44d7ee4730fbe3c00aba0457489acd0b6e2937c9 Mon Sep 17 00:00:00 2001 |
| From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> |
| Date: Wed, 4 Dec 2019 13:56:33 +0100 |
| Subject: [PATCH] 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 <nsaenzjulienne@suse.de> |
| Reviewed-by: Phil Elwell <phil@raspberrypi.org> |
| Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> |
| --- |
| arch/arm/boot/dts/bcm2711.dtsi | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- 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 |