From: Manuel Reimer <Manuel.Spam@nurfuerspam.de>
To: linux-kernel@vger.kernel.org
Subject: Re: 3.15.4 runs *significantly* slower than 3.15.3 on iMX233 CPU
Date: Mon, 07 Jul 2014 21:55:06 +0200 [thread overview]
Message-ID: <lpetuq$bt8$1@ger.gmane.org> (raw)
In-Reply-To: <20140707194223.GA29819@roeck-us.net>
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
next prev parent reply other threads:[~2014-07-07 19:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-07 18:21 3.15.4 runs *significantly* slower than 3.15.3 on iMX233 CPU Manuel Reimer
2014-07-07 19:14 ` Guenter Roeck
2014-07-07 19:29 ` Manuel Reimer
2014-07-07 19:42 ` Guenter Roeck
2014-07-07 19:55 ` Manuel Reimer [this message]
2014-07-07 20:37 ` Geert Uytterhoeven
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