diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0953-ARM-dts-bcm2835-Use-the-L2-non-allocating-alias.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-5.4/950-0953-ARM-dts-bcm2835-Use-the-L2-non-allocating-alias.patch | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0953-ARM-dts-bcm2835-Use-the-L2-non-allocating-alias.patch b/target/linux/bcm27xx/patches-5.4/950-0953-ARM-dts-bcm2835-Use-the-L2-non-allocating-alias.patch new file mode 100644 index 0000000000..d87ffc8c22 --- /dev/null +++ b/target/linux/bcm27xx/patches-5.4/950-0953-ARM-dts-bcm2835-Use-the-L2-non-allocating-alias.patch @@ -0,0 +1,30 @@ +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 { |