From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755143AbZFMF5I (ORCPT ); Sat, 13 Jun 2009 01:57:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751491AbZFMF4y (ORCPT ); Sat, 13 Jun 2009 01:56:54 -0400 Received: from mail-yx0-f200.google.com ([209.85.210.200]:52576 "EHLO mail-yx0-f200.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752070AbZFMF4y (ORCPT ); Sat, 13 Jun 2009 01:56:54 -0400 X-Greylist: delayed 411 seconds by postgrey-1.27 at vger.kernel.org; Sat, 13 Jun 2009 01:56:53 EDT DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=Lp9y07dPsBrftbhQAxLoNgRjB/eH8feWWwNj3pZV6fizNQ+9WEBfLSxVEay+pFkYqn HbgssLZsnebrwJCvkOZAaJtOdHFbaOkRKAdfHmJ8g2cmxQ490ZMIBBIV5gI1baprwfpy YYXLO/d7sqBuCHFuqS9AIWEILAzth9wbPPKIA= Message-ID: <4A333E0D.8050306@gmail.com> Date: Fri, 12 Jun 2009 23:50:05 -0600 From: Robert Hancock User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1b3pre) Gecko/20090513 Fedora/3.0-2.3.beta2.fc11 Thunderbird/3.0b2 MIME-Version: 1.0 To: Sanka Piyaratna CC: linux-kernel@vger.kernel.org Subject: Re: PCIe interface memory memory mapping issue References: <233030.36441.qm@web31706.mail.mud.yahoo.com> In-Reply-To: <233030.36441.qm@web31706.mail.mud.yahoo.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/12/2009 06:23 AM, Sanka Piyaratna wrote: > Hi, > > I have developed a PCI express interface using Xilinx ML555 hardware module. I have implemented Linux kernel mode device drivers and everything works correctly as long as I am using the device within a computer with dual channel DDR arrangement. However, as soon as I pug this device into a core i7 or an older single channel DDR machine, the interface memory mapping does not work any more. As if the register map with in the device does no longer exsists. However, "lspci" utility provides correct information. I am not sure if this has anything to do with the number of DDR memory channels the motherboard has or why that would be a problem for PCI express device. However, this seem to be the common link between the machines that demonstrate this issue. You'll have to give more details on what you mean by "the interface memory mapping does not work any more. As if the register map with in the device does no longer exsists".