Re: 3.15.4 runs *significantly* slower than 3.15.3 on iMX233 CPU
From: Manuel Reimer
Date: Mon Jul 07 2014 - 15:55:30 EST
On 07/07/2014 09:42 PM, Guenter Roeck wrote:
I tracked the problem down to the following patch:
diff --git a/arch/arm/boot/dts/imx23-olinuxino.dts
b/arch/arm/boot/dts/imx23-olinuxino.dts
index d107c4a..993da2e 100644
--- a/arch/arm/boot/dts/imx23-olinuxino.dts
+++ b/arch/arm/boot/dts/imx23-olinuxino.dts
@@ -64,7 +64,14 @@
compatible = "fsl,imx23-spi";
pinctrl-names = "default";
pinctrl-0 = <&spi2_pins_a>;
+ clock-frequency = <1000000>;
If I understand the code correctly, that means you reduce the access speed
for SPI flashes from 160 MHz down to 1 MHz.
If so, and if your system loads anything from a SPI flash, I would not be too
surprised that your system is now a bit on the slow side.
The iMX233 has two separate SPI connections. The first one is used to
connect to the SD card where the system boots from and the second one is
the one I plan to use. The idea was to only set clock frequency for the
SPI bus, I want to use to connect to external devices. The "SD SPI" has
to run with "full speed". So where is the mistake...
Thanks in advance.
Greetings,
Manuel
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