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authorMaxime Coquelin <mcoquelin.stm32@gmail.com>2015-12-02 17:47:17 +0100
committerMaxime Coquelin <mcoquelin.stm32@gmail.com>2016-02-11 12:02:59 +0100
commitb2aa7f7741f511c6a1ea266d62d203662f121ea7 (patch)
tree06febcaf3c140087623d9ea0feb509da1e2b0f4d /arch/arm/boot/dts/stm32429i-eval.dts
parentARM: dts: Add leds support to STM32F429 boards (diff)
downloadlinux-b2aa7f7741f511c6a1ea266d62d203662f121ea7.tar.xz
linux-b2aa7f7741f511c6a1ea266d62d203662f121ea7.zip
ARM: dts: stm32f429: Boost perfs by remapping SDRAM Bank 1 to 0x0
STM32F429 allows to remap FMC SDRAM Bank 1 from 0xc0000000 to 0x0, by writing 0x4 to SYSCFG_MEMRMP register. As mentionned in the reference manual (see chapter 9.3.1), the performance gain is really interresting: "In remap mode at address 0x0000 0000, the CPU can access the external memory via ICode bus instead of System bus which boosts up the performance." These are the dhrystone results with and without the remap enabled: Default (SDRAM in 0xc0000000): --------------------------------- Microseconds for one run through Dhrystone: 31.8 Dhrystones per Second: 31416.9 Remap (SDRAM in 0x0000000): ----------------------------- Microseconds for one run through Dhrystone: 20.6 Dhrystones per Second: 48520.1 This patch first change the SDRAM start address to 0x0 for STM32429i-EVAL board, and also set the dma-range property as the other masters than the M4 CPU still see SDRAM in 0xc0000000. Note that the Discovery board cannot benefit from this feature, since the SDRAM is connected to Bank 2. Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Diffstat (limited to 'arch/arm/boot/dts/stm32429i-eval.dts')
-rw-r--r--arch/arm/boot/dts/stm32429i-eval.dts2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/boot/dts/stm32429i-eval.dts b/arch/arm/boot/dts/stm32429i-eval.dts
index e3921d9b00c6..1ae57fad12d3 100644
--- a/arch/arm/boot/dts/stm32429i-eval.dts
+++ b/arch/arm/boot/dts/stm32429i-eval.dts
@@ -58,7 +58,7 @@
};
memory {
- reg = <0xc0000000 0x2000000>;
+ reg = <0x00000000 0x2000000>;
};
aliases {