Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755087Ab0BAW1j (ORCPT ); Mon, 1 Feb 2010 17:27:39 -0500 Received: from einhorn.in-berlin.de ([192.109.42.8]:42521 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755002Ab0BAW1h (ORCPT ); Mon, 1 Feb 2010 17:27:37 -0500 X-Envelope-From: stefanr@s5r6.in-berlin.de Message-ID: <4B675534.5070107@s5r6.in-berlin.de> Date: Mon, 01 Feb 2010 23:27:00 +0100 From: Stefan Richter User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.23) Gecko/20100102 SeaMonkey/1.1.18 MIME-Version: 1.0 To: "Justin P. Mattock" CC: Dan Carpenter , linux1394-devel@lists.sourceforge.net, "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List Subject: Re: ohci1394_dma=early crash since 2.6.32 (was Re: [Bug #14487] PANIC: early exception 08 rip 246:10 error ffffffff810251b5 cr2 0) References: <4B6630CA.9010207@gmail.com> <20100201125441.GB2576@bicker> <4B671606.3080405@gmail.com> <4B673233.8000300@s5r6.in-berlin.de> <4B6740B5.5070601@gmail.com> In-Reply-To: <4B6740B5.5070601@gmail.com> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1523 Lines: 34 Justin P. Mattock wrote: > (as for yesterdays 0xffffffffffffffff(just experimenting)Google gives me > no info on the differences between 8f's to 16f's, I was under the > impression that it's x86_32 and x86_64 for the pci address). As Dan noted, (class == 0xffffffff || 0xffffffffffffffff) is always true because it is logically the same as (class == whatever) || true If you really meant class == 0xffffffff || class == 0xffffffffffffffff then the latter half will never become true because class is declared as u32 and got its value from read_pci_config() which also returns u32. BTW, whether a PCI device is capable of accessing 32 bit bus addresses or also 64 bit bus addresses depends on the device, not on the CPU. Originally, PCI only had a 32 bit addressing model. OHCI 1394 1.0/1.1 implementations only deal with 32 bit local bus addresses. The 'class' however is not an address but merely a register value with 24 bits width. (Defined in the PCI Local Bus spec which is not freely available, cited in OHCI 1394 annex A.3.) This register is read as a 32 bits wide register from which the excess byte is later discarded. If all bits read are 1, the bus:slot:function is not actually populated. -- Stefan Richter -=====-==-=- --=- ----= http://arcgraph.de/sr/ -- 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/