Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751943AbaGGTz0 (ORCPT ); Mon, 7 Jul 2014 15:55:26 -0400 Received: from plane.gmane.org ([80.91.229.3]:59662 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbaGGTzY (ORCPT ); Mon, 7 Jul 2014 15:55:24 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Manuel Reimer Subject: Re: 3.15.4 runs *significantly* slower than 3.15.3 on iMX233 CPU Date: Mon, 07 Jul 2014 21:55:06 +0200 Lines: 32 Message-ID: References: <20140707191430.GA23004@roeck-us.net> <20140707194223.GA29819@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: p5dd560e1.dip0.t-ipconnect.de User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 In-Reply-To: <20140707194223.GA29819@roeck-us.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/