Messages in this thread | | | Date | Mon, 7 Jul 2014 12:42:23 -0700 | From | Guenter Roeck <> | Subject | Re: 3.15.4 runs *significantly* slower than 3.15.3 on iMX233 CPU |
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On Mon, Jul 07, 2014 at 09:29:21PM +0200, Manuel Reimer wrote: > On 07/07/2014 09:14 PM, Guenter Roeck wrote: > >Are you sure this did not just happen when you booted the new kernel > >for the first time ? I have seen similar behavior with some distributions. > > I did some more tries and found out that I had disabled some of my > patches until I reached 3.15.4 (latest version) where I decided to > do needed modifications to get my patches back in. > > 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.
Guenter
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