Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755386AbYGKQ4H (ORCPT ); Fri, 11 Jul 2008 12:56:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754046AbYGKQzz (ORCPT ); Fri, 11 Jul 2008 12:55:55 -0400 Received: from smtp8.server.rpi.edu ([128.113.2.228]:49983 "EHLO smtp8.server.rpi.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753895AbYGKQzy (ORCPT ); Fri, 11 Jul 2008 12:55:54 -0400 Message-ID: <4877908C.4060706@rpi.edu> Date: Fri, 11 Jul 2008 12:55:40 -0400 From: David Brigada User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: Jordan Crouse CC: jim.cromie@gmail.com, LKML , linux-geode@lists.infradead.org Subject: Re: PCI-ISA Bridge not operating References: <487774F9.6000001@rpi.edu> <20080711164845.GB28720@cosmic.amd.com> (sfid-20080711_174547_429140_033022C1) In-Reply-To: <20080711164845.GB28720@cosmic.amd.com> (sfid-20080711_174547_429140_033022C1) Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-RPI-SA-Score: undef - spam scanning disabled X-CanItPRO-Stream: default X-Canit-Stats-ID: Bayes signature not available Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2429 Lines: 55 Jordan Crouse wrote: > On 11/07/08 10:58 -0400, David Brigada wrote: >> Hi, >> >> I'm working with the MSM800XEV board from Digital-Logic. This board >> uses a Geode LX800 for a CPU and has the CS5536 companion board also >> installed. The board works with an IT8888G IC that provides a PCI/ISA >> bridge to a PC/104 bus that is externally provided. >> >> If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA >> signaling comes over the PC/104 bus. In Linux, the /IOW or /IOR line >> goes low as expected, but the address doesn't come over the bus. The >> DOS that I'm running doesn't seem to have any specific drivers for the >> chip, I'm guessing that the hardware should "just work" --- the IT8888G >> is designed to grab I/O requests in the ISA range off the PCI bus after >> a short delay if nothing else grabs them first. >> >> I have a feeling that it has something to do with the CS5536 companion >> chip, as it seems as though there is a driver for a PCI/ISA bridge on >> that chip, though I can't get much detail from AMD's datasheet on that >> functionality. I do know that on the MSM800XEV, any such functionality >> is wired to the IT8888G, not the CS5536. >> >> There are two kernel config options related to the PCI IDs of the parts >> of the device that handle the ISA bus, CONFIG_SCx200_ACB and >> CONFIG_CS5535_GPIO. I've tried disabling both, but it doesn't seem to help. >> >> In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G. >> >> Any ideas? > > ISA should indeed "just work". The only thing I'm wondering is if > the kernel is interfering (it shouldn't). I assume that since it works > in FreeDOS that there is no possibility that something on the PCI bus > is grabbing the cycles instead. That's what I'm thinking --- that the CS5536 PCI/ISA bridge is claiming the cycles. > How are you trying to access the device in Linux? Through a kernel module > or a user application running as root? I've tried both. I have a kernel module that I wrote for the hardware. When I couldn't get that working, I tried looping some code that keeps touching the same I/O port that I'm using. > Jordan > Dave -- 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/