From 121fdf16a2ff4cf651c376a37eeca255544c47fd Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Thu, 27 Aug 2020 17:57:18 +0100 Subject: [PATCH] ARM: dts: bcm2835: Use the L2 non-allocating alias The /soc/dma-ranges property on BCM2835 currently results in DMA addresses in the range 0x40000000-0x5fffffff. This will allocate in the system L2 cache, which may adversely affect performance. Change the dma-ranges property to give addresses in the range 0x80000000-0x9fffffff, which are coherent with L2 but non-allocating. See: https://github.com/raspberrypi/linux/issues/3602 Signed-off-by: Phil Elwell --- arch/arm/boot/dts/bcm2835.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm/boot/dts/bcm2835.dtsi +++ b/arch/arm/boot/dts/bcm2835.dtsi @@ -18,7 +18,7 @@ soc { ranges = <0x7e000000 0x20000000 0x02000000>; - dma-ranges = <0x40000000 0x00000000 0x20000000>; + dma-ranges = <0x80000000 0x00000000 0x20000000>; }; arm-pmu {