Openwrt/target/linux/bcm27xx/patches-5.4/950-0953-ARM-dts-bcm2835-Use-the-L2-non-allocating-alias.patch
Álvaro Fernández Rojas f07e572f64 bcm27xx: import latest patches from the RPi foundation
bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2021-02-18 23:42:32 +01:00

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Diff

From 121fdf16a2ff4cf651c376a37eeca255544c47fd Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
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 <phil@raspberrypi.com>
---
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 {