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Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0421-ARM-dts-bcm2711-fix-soc-s-node-dma-ranges.patch')
-rw-r--r--target/linux/bcm27xx/patches-5.4/950-0421-ARM-dts-bcm2711-fix-soc-s-node-dma-ranges.patch40
1 files changed, 40 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0421-ARM-dts-bcm2711-fix-soc-s-node-dma-ranges.patch b/target/linux/bcm27xx/patches-5.4/950-0421-ARM-dts-bcm2711-fix-soc-s-node-dma-ranges.patch
new file mode 100644
index 0000000000..ed0be9b9a3
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0421-ARM-dts-bcm2711-fix-soc-s-node-dma-ranges.patch
@@ -0,0 +1,40 @@
+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